----

**UNITED      STATES**

**SECURITIES      AND EXCHANGE COMMISSION**

**WASHINGTON,      D.C. 20549**

**FORM      10-Q**

| **[X]**                                                                                                                                                                                                                                                                                                  | **QUARTERLY                REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE                ACT OF                1934**  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                                                                                                                                                                     |
| For                the quarterly period ended June 30, 2006                                                                                                                                                                                                                                              |
|                                                                                                                                                                                                                                                                                                     |
|                                                                                                                                                                                                                                                                                                     | or                                                                                                                                        |
|                                                                                                                                                                                                                                                                                                     |                                                                                                                                      |
| **[                  ]**                                                                                                                                                                                                                                                                       | **TRANSITION                REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE                ACT OF                1934** |
|                                                                                                                                                                                                                                                                                                     |                                                                                                                                      |
| For                the transition period                from                                       to |

**KNIGHT      TRANSPORTATION, INC.**

| **Arizona**                                                                                 | **86-0649974**                                                    |
|---------------------------------------------------------------------------------------------|-------------------------------------------------------------------|
| (State                or other jurisdiction ofincorporation                or organization) | (I.R.S.                EmployerIdentification                No.) |

**5601      West Buckeye Road**

**Phoenix,      Arizona**

**85043**

**602-269-2000**

| Large                accelerated filer [X] | Accelerated                filer [   ] | Non-accelerated                filer [   ] |
|--------------------------------------------|--------------------------------------------------|------------------------------------------------------|

      [   ] Yes        [X] No

----

**KNIGHT      TRANSPORTATION, INC.**

**INDEX**

| **PART                    I -****FINANCIAL                    INFORMATION** | **Page****Number**                                                                                                                                                  |
|-----------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                        |                                                                                                                                                                |
| **Item                    1.**                                              | **Financial                    Statements**                                                                                                                         |   |
|                                                                        |                                                                                                                                                                |   |
|                                                                        | Condensed                    Consolidated Balance Sheets as of June 30, 2006 and                    December 31, 2005                    (Unaudited)                | 3 |
|                                                                        |                                                                                                                                                                |   |
|                                                                        | Condensed                    Consolidated Statements of Income for the three and six months                    ended June 30, 2006 and 2005 (Unaudited)             | 5 |
|                                                                        |                                                                                                                                                                |   |
|                                                                        | Condensed                    Consolidated Statements of Cash Flows for the sixmonths                    ended June 30, 2006 and                    2005 (Unaudited) | 6 |
|                                                                        |                                                                                                                                                                |   |
|                                                                        | Notes                    to Condensed Consolidated Financial Statements (Unaudited)                                                                                 | 8 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    2.**                                              | **Management's                    Discussion and Analysis of Financial Condition****and                    Results of                    Operation**                | 13 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    3.**                                              | **Quantitative                    and Qualitative Disclosures About Market Risk**                                                                                   | 20 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    4.**                                              | **Controls                    and Procedures**                                                                                                                      | 21 |
|                                                                        |                                                                                                                                                                |   |
| **Part                    II -****OTHER INFORMATION**                       |                                                                                                                                                                |
|                                                                        |                                                                                                                                                                |   |
| **Item                    1.**                                              | **Legal                    Proceedings**                                                                                                                            | 22 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    1A.**                                             | **Risk                    Factors**                                                                                                                                 | 22 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    2.**                                              | **Unregistered                    Sales of Equity Securities and Use of Proceeds**                                                                                  | 22 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    3.**                                              | **Defaults                    Upon Senior Securities**                                                                                                              | 22 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    4.**                                              | **Submission                    of Matters to a Vote of Security Holders**                                                                                          | 22 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    5.**                                              | **Other                    Information**                                                                                                                            | 23 |
|                                                                        |                                                                                                                                                                |   |
| **Item                    6.**                                              | **Exhibits**                                                                                                                                                        | 23 |
|                                                                        |                                                                                                                                                                |   |
| **Signatures**                                                              |                                                                                                                                                                | 25 |

----

INDEX

| **PART                I - FINANCIAL INFORMATION**                        |
|-------------------------------------------------------------------------------|
| **Item                1.**  **Financial                Statements** |

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Balance Sheets****(unaudited)****As                of June 30, 2006 and December 31, 2005****(In                thousands)** |   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                                                                |   |
|                                                                                                                                                                                                                                |   | June                30, 2006 |   | December                31, 2005 |   |
|                                                                                                                                                                                                                                |   |   |   |   |   |
| **ASSETS**                                                                                                                                                                                                                          |   |   |   |   |   |
|                                                                                                                                                                                                                                |   |   |   |   |   |
| Current                Assets:                                                                                                                                                                                                      |   |   |   |   |   |
| Cash                and cash                equivalents                                                                                                                                                                             |   | $ | 17,973 |   | $ | 18,809 |   |
| Short-term                investments                                                                                                                                                                                               |   |   | 5,176 |   |   | 2,278 |   |
| Accounts                receivable,                net                                                                                                                                                                              |   |   | 77,983 |   |   | 79,848 |   |
| Notes                receivable,                net                                                                                                                                                                                 |   |   | 277 |   |   | 241 |   |
| Inventories                and                supplies                                                                                                                                                                              |   |   | 3,656 |   |   | 3,355 |   |
| Prepaid                expenses                                                                                                                                                                                                     |   |   | 8,670 |   |   | 7,156 |   |
| Restricted                cash                                                                                                                                                                                                      |   |   | - |   |   | 211 |   |
| Deferred                tax                asset                                                                                                                                                                                    |   |   | 8,244 |   |   | 8,533 |   |
|                                                                                                                                                                                                                                |   |   |   |   |   |   |   |
| Total                current assets                                                                                                                                                                                                 |   |   | 121,979 |   |   | 120,431 |   |
|                                                                                                                                                                                                                                |   |   |   |   |   |   |   |
| Property                and Equipment:                                                                                                                                                                                              |   |   |   |   |   |   |   |
| Land                and                improvements                                                                                                                                                                                 |   |   | 20,145 |   |   | 18,163 |   |
| Buildings                and                improvements                                                                                                                                                                            |   |   | 35,528 |   |   | 34,482 |   |
| Furniture                and                fixtures                                                                                                                                                                                |   |   | 6,418 |   |   | 7,518 |   |
| Shop                and service                equipment                                                                                                                                                                            |   |   | 3,192 |   |   | 2,803 |   |
| Revenue                equipment                                                                                                                                                                                                    |   |   | 461,513 |   |   | 430,048 |   |
| Leasehold                improvements                                                                                                                                                                                               |   |   | 422 |   |   | 378 |   |
|                                                                                                                                                                                                                                |   |   |   |   |   |   |   |
|                                                                                                                                                                                                                                |   |   | 527,218 |   |   | 493,392 |   |
| Less:                Accumulated depreciation                and                amortization                                                                                                                                        |   |   | (141,465 | ) |   | (141,053 | ) |
|                                                                                                                                                                                                                                |   |   |   |   |   |   |   |
| Property                and equipment, net                                                                                                                                                                                          |   |   | 385,753 |   |   | 352,339 |   |
|                                                                                                                                                                                                                                |   |   |   |   |   |   |   |
| Notes                receivable - long-term                                                                                                                                                                                         |   |   | 376 |   |   | 344 |   |
| Goodwill                                                                                                                                                                                                                            |   |   | 8,439 |   |   | 8,119 |   |
| Other                assets & restricted cash                                                                                                                                                                                   |   |   | 4,400 |   |   | 2,594 |   |
|                                                                                                                                                                                                                                |   |   |   |   |   |   |   |
|                                                                                                                                                                                                                                |   | $ | 520,947 |   | $ | 483,827 |   |

----

INDEX

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Balance Sheets (unaudited) (continued)****As                of June 30, 2006 and December 31, 2005****(In                thousands, except par values)**                                            |   |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |
|                                                                                                                                                                                                                                                                                                       |   | June                30, 2006 |   | December                31, 2005 |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |
| **LIABILITIES                AND SHAREHOLDERS' EQUITY**                                                                                                                                                                                                                                                    |   |   |   |   |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |
| Current                Liabilities:                                                                                                                                                                                                                                                                        |   |   |   |   |   |
| Accounts                payable                                                                                                                                                                                                                                                                            |   | $ | 9,668 |   | $ | 7,464 |   |
| Accrued                payroll                                                                                                                                                                                                                                                                             |   |   | 6,641 |   |   | 5,452 |   |
| Accrued                liabilities                                                                                                                                                                                                                                                                         |   |   | 16,468 |   |   | 13,307 |   |
| Claims                accrual                                                                                                                                                                                                                                                                              |   |   | 23,049 |   |   | 26,155 |   |
| Other                current                liabilities                                                                                                                                                                                                                                                    |   |   | - |   |   | 211 |   |
| Dividend                payable                                                                                                                                                                                                                                                                            |   |   | - |   |   | 1,713 |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |   |   |
| Total                current liabilities                                                                                                                                                                                                                                                                   |   |   | 55,826 |   |   | 54,302 |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |   |   |
| Deferred                tax liabilities                                                                                                                                                                                                                                                                    |   |   | 78,149 |   |   | 76,597 |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |   |   |
| Total                liabilities                                                                                                                                                                                                                                                                           |   |   | 133,975 |   |   | 130,899 |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |   |   |
| Commitments                and Contingencies                                                                                                                                                                                                                                                               |   |   |   |   |   |   |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |   |   |
| Shareholders'                Equity:                                                                                                                                                                                                                                                                       |   |   |   |   |   |   |   |
| Preferred                stock, $0.01 par                value;50,000                shares authorized;none                issued and outstanding                                                                                                                                                          |   |   | - |   |   | - |   |
| Common                stock, $0.01 par value;                100,000 shares                authorized;           85,864                and 85,666 shares issued and outstanding at                June 30, 2006 and December 31, 2005, respectively |   |   | 859 |   |   | 857 |   |
| Additional                paid-in                capital                                                                                                                                                                                                                                                   |   |   | 90,672 |   |   | 87,148 |   |
| Retained                earnings                                                                                                                                                                                                                                                                           |   |   | 295,441 |   |   | 264,923 |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |   |   |
| Total                shareholders' equity                                                                                                                                                                                                                                                                  |   |   | 386,972 |   |   | 352,928 |   |
|                                                                                                                                                                                                                                                                                                       |   |   |   |   |   |   |   |
|                                                                                                                                                                                                                                                                                                       |   | $ | 520,947 |   | $ | 483,827 |   |

----

INDEX

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Statements of Income (unaudited)****(In                thousands, except per share data)**  |   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                                    |   | Three                Months EndedJune                30, |   | Six                Months EndedJune                30, |   |
|                                                                                                                                                                                                    |   | 2006 |   | 2005 |   | 2006 |   | 2005 |   |
| REVENUE:                                                                                                                                                                                                |   |   |   |   |   |   |   |   |   |
| Revenue,                before fuel surcharge                                                                                                                                                           |   | $ | 140,372 |   | $ | 119,722 |   | $ | 269,711 |   | $ | 230,797 |   |
| Fuel                surcharge                                                                                                                                                                           |   |   | 25,395 |   |   | 14,145 |   |   | 45,108 |   |   | 25,252 |   |
| Total                revenue                                                                                                                                                                            |   |   | 165,767 |   |   | 133,867 |   |   | 314,819 |   |   | 256,049 |   |
| OPERATING                EXPENSES:                                                                                                                                                                      |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Salaries,                wages and                benefits                                                                                                                                              |   |   | 47,861 |   |   | 39,196 |   |   | 91,063 |   |   | 76,114 |   |
| Fuel                                                                                                                                                                                                    |   |   | 43,224 |   |   | 30,192 |   |   | 79,247 |   |   | 56,033 |   |
| Operations                and                maintenance                                                                                                                                                |   |   | 8,286 |   |   | 8,171 |   |   | 17,714 |   |   | 15,803 |   |
| Insurance                and                claims                                                                                                                                                      |   |   | 6,108 |   |   | 5,940 |   |   | 11,862 |   |   | 12,304 |   |
| Operating                taxes and                licenses                                                                                                                                              |   |   | 3,341 |   |   | 2,964 |   |   | 6,592 |   |   | 5,894 |   |
| Communications                                                                                                                                                                                          |   |   | 1,428 |   |   | 952 |   |   | 2,737 |   |   | 1,927 |   |
| Depreciation                and                amortization                                                                                                                                             |   |   | 14,993 |   |   | 12,786 |   |   | 29,593 |   |   | 25,096 |   |
| Lease                expense - revenue                equipment                                                                                                                                         |   |   | 108 |   |   | - |   |   | 217 |   |   | - |   |
| Purchased                transportation                                                                                                                                                                 |   |   | 9,832 |   |   | 7,127 |   |   | 17,738 |   |   | 13,611 |   |
| Miscellaneous                operating                expenses                                                                                                                                          |   |   | 658 |   |   | 1,725 |   |   | 2,030 |   |   | 3,305 |   |
| Total                operating expenses                                                                                                                                                                 |   |   | 135,839 |   |   | 109,053 |   |   | 258,793 |   |   | 210,087 |   |
|                                                                                                                                                                                                    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Income                from operations                                                                                                                                                                   |   |   | 29,928 |   |   | 24,814 |   |   | 56,026 |   |   | 45,962 |   |
|                                                                                                                                                                                                    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Interest                and investment income                                                                                                                                                           |   |   | 293 |   |   | 143 |   |   | 577 |   |   | 253 |   |
|                                                                                                                                                                                                    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Income                before income taxes                                                                                                                                                               |   |   | 30,221 |   |   | 24,957 |   |   | 56,603 |   |   | 46,215 |   |
|                                                                                                                                                                                                    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Income                taxes                                                                                                                                                                             |   |   | (12,100 | ) |   | (10,000 | ) |   | (22,650 | ) |   | (18,500 | ) |
|                                                                                                                                                                                                    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Net                income                                                                                                                                                                               |   | $ | 18,121 |   | $ | 14,957 |   | $ | 33,953 |   | $ | 27,715 |   |
|                                                                                                                                                                                                    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Earnings                per common share and common share equivalent:                                                                                                                                   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Basic                                                                                                                                                                                                   |   | $ | 0.21 |   | $ | 0.18 |   | $ | 0.40 |   | $ | 0.33 |   |
| Diluted                                                                                                                                                                                                 |   | $ | 0.21 |   | $ | 0.17 |   | $ | 0.39 |   | $ | 0.32 |   |
|                                                                                                                                                                                                    |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Weighted                average number of common shares and common share equivalents                outstanding:                                                                                        |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Basic                                                                                                                                                                                                   |   |   | 85,830 |   |   | 85,223 |   |   | 85,788 |   |   | 85,172 |   |
| Diluted                                                                                                                                                                                                 |   |   | 87,113 |   |   | 86,966 |   |   | 87,141 |   |   | 87,020 |   |

----

INDEX

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Statements of Cash Flows (unaudited)****(In                thousands)** |   |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                           |   |   |   |
|                                                                                                                                                                           |   | Six                Months EndedJune                30, |   |
|                                                                                                                                                                           |   |   |   |
|                                                                                                                                                                           |   | 2006 |   | 2005 |   |
| CASH                FLOWS FROM OPERATING ACTIVITIES:                                                                                                                           |   |   |   |   |   |
|                                                                                                                                                                           |   |   |   |   |   |
| Net                income                                                                                                                                                      |   | $ | 33,953 |   | $ | 27,715 |   |
| Adjustments                to reconcile net income to net cash provided by operating                activities:                                                                |   |   |   |   |   |   |   |
| Depreciation                and amortization                                                                                                                                   |   |   | 29,593 |   |   | 25,096 |   |
| Gain                on sales of equipment                                                                                                                                      |   |   | (4,726 | ) |   | (1,320 | ) |
| Non-cash                compensation expense for issuance of stock to certainmembers                of board of directors                                                      |   |   | 33 |   |   | 15 |   |
| Provision                for allowance for doubtful accounts                                                                                                                   |   |   | (57 | ) |   | (65 | ) |
| Tax                benefit on stock option exercises                                                                                                                           |   |   | - |   |   | 844 |   |
| Tax                benefits related to stock-based compensation                                                                                                                |   |   | (733 | ) |   | - |   |
| Stock                option expense                                                                                                                                            |   |   | 1,604 |   |   | - |   |
| Deferred                income taxes                                                                                                                                           |   |   | 1,842 |   |   | (965 | ) |
| Changes                in assets and liabilities:                                                                                                                              |   |   |   |   |   |   |   |
| (Increase)                in short-term investments                                                                                                                            |   |   | (2,898 | ) |   | - |   |
| Decrease                (increase) in trade receivables                                                                                                                        |   |   | 1,922 |   |   | (5,840 | ) |
| (Increase)                in inventories and supplies                                                                                                                          |   |   | (301 | ) |   | (745 | ) |
| (Increase)                in prepaid expenses                                                                                                                                  |   |   | (1,514 | ) |   | (1,469 | ) |
| Decrease                in income tax receivable                                                                                                                               |   |   | - |   |   | 3,216 |   |
| (Increase)                decrease in other assets                                                                                                                             |   |   | (126 | ) |   | 598 |   |
| Increase                (decrease) in accounts payable                                                                                                                         |   |   | 1,340 |   |   | (1,781 | ) |
| Increase                in accrued liabilities, claims accrual and other                                                                                                       |   |   | 1,766 |   |   | 7,986 |   |
|                                                                                                                                                                           |   |   |   |   |   |   |   |
| Net                cash provided by operating activities                                                                                                                       |   |   | 61,698 |   |   | 53,285 |   |
|                                                                                                                                                                           |   |   |   |   |   |   |   |
| CASH                FLOW FROM INVESTING ACTIVITIES:                                                                                                                            |   |   |   |   |   |   |   |
|                                                                                                                                                                           |   |   |   |   |   |   |   |
| Purchase                of property and equipment                                                                                                                              |   |   | (83,390 | ) |   | (43,646 | ) |
| Proceeds                from sales of equipment                                                                                                                                |   |   | 25,974 |   |   | 6,050 |   |
| Increase                in notes receivable                                                                                                                                    |   |   | (69 | ) |   | (180 | ) |
| Acquisition-related                contingent payment                                                                                                                          |   |   | (320 | ) |   | - |   |
| (Increase)                in restricted cash                                                                                                                                   |   |   | (384 | ) |   | - |   |
| TRP                investment                                                                                                                                                  |   |   | (1,085 | ) |   | - |   |
|                                                                                                                                                                           |   |   |   |   |   |   |   |
| Net                cash used in investing activities                                                                                                                           |   |   | (59,274 | ) |   | (37,776 | ) |

----

INDEX

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Statements of Cash Flows (unaudited)****(In                thousands)**  |   |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                 |   | Six                Months EndedJune                30, |   |
|                                                                                                                                                                                 |   |   |   |
|                                                                                                                                                                                 |   | 2006 |   | 2005 |   |
|  CASH                FLOW FROM FINANCING ACTIVITIES:                                                                                                                            |   |   |   |   |   |
|                                                                                                                                                                                 |   |   |   |   |   |
| Dividends                paid                                                                                                                                                        |   |   | (5,148 | ) |   | (1,136 | ) |
| Tax                benefits related to stock-based compensation                                                                                                                      |   |   | 733 |   |   | - |   |
| Proceeds                from exercise of stock options                                                                                                                               |   |   | 1,155 |   |   | 1,193 |   |
|                                                                                                                                                                                 |   |   |   |   |   |   |   |
| Net                cash (used in) provided by financing activities                                                                                                                   |   |   | (3,260 | ) |   | 57 |   |
|                                                                                                                                                                                 |   |   |   |   |   |   |   |
| NET                (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS                                                                                                                  |   |   | (836 | ) |   | 15,566 |   |
| CASH                AND CASH EQUIVALENTS, beginning of period                                                                                                                        |   |   | 18,809 |   |   | 25,357 |   |
|                                                                                                                                                                                 |   |   |   |   |   |   |   |
| CASH                AND CASH EQUIVALENTS, end of period                                                                                                                              |   | $ | 17,973 |   | $ | 40,923 |   |
|                                                                                                                                                                                 |   |   |   |   |   |   |   |
| SUPPLEMENTAL                DISCLOSURES:                                                                                                                                             |   |   |   |   |   |   |   |
|                                                                                                                                                                                 |   |   |   |   |   |   |   |
| Non-cash                investing and financing transactions:                                                                                                                        |   |   |   |   |   |   |   |
| Equipment                acquired in accounts payable                                                                                                                                |   | $ | 2,765 |   | $ | 1,277 |   |
|                                                                                                                                                                                 |   |   |   |   |   |   |   |
| Cash                Flow Information:                                                                                                                                                |   |   |   |   |   |   |   |
| Income                taxes paid                                                                                                                                                     |   | $ | 21,294 |   | $ | 10,851 |   |

----

INDEX

**KNIGHT      TRANSPORTATION, INC. AND SUBSIDIARIES**

**NOTES      TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Unaudited)**

**Note      1.**
**Financial      Information**

**Note      2.**
**Stock-Based      Compensation**

----

INDEX

|                                                                                                                                                           |   | Three                Months Ended |   | Six                Months Ended |   |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|-----------------------------------|--------|---------------------------------|--------|
|                                                                                                                                                           |   | June                30, 2005      |   | June                30, 2005    |   |
|                                                                                                                                                           |   |                              |   |                            |   |
| Net                income, as reported                                                                                                                         |   | $                                 | 14,957 |                            | $      | 27,715 |   |
|                                                                                                                                                           |   |                              |   |                            |   |   |   |
| Deduct                total stock-based compensation expense                determined under fair-value based method                for all awards, net of tax |   |                              | (646   | )                               |   | (930 | ) |
|                                                                                                                                                           |   |                              |   |                            |   |   |   |
| Pro                forma net income                                                                                                                            |   | $                                 | 14,311 |                            | $      | 26,785 |   |
|                                                                                                                                                           |   |                              |   |                            |   |   |   |
| Basic                earnings per share:                                                                                                                       |   |                              |   |                            |   |   |   |
| As                reported                                                                                                                                     |   | $                                 | 0.18   |                            | $      | 0.33 |   |
| Pro                forma                                                                                                                                       |   | $                                 | 0.17   |                            | $      | 0.31 |   |
|                                                                                                                                                           |   |                              |   |                            |   |   |   |
| Diluted                earnings per share:                                                                                                                     |   |                              |   |                            |   |   |   |
| As                reported                                                                                                                                     |   | $                                 | 0.17   |                            | $      | 0.32 |   |
| Pro                forma                                                                                                                                       |   | $                                 | 0.16   |                            | $      | 0.31 |   |

|                                                          |   | Quarter                EndedJune                30, |                      |
|---------------------------------------------------------------|--------|-----------------------------------------------------|---------------------------|
|                                                          |   |                                                |                      |   |   |
|                                                          |   | 2006                                                |                      | 2005 |   |
|                                                          |   |                                                |                      |   |   |
| Dividend                yield (1)                             |   |                                                | .43                       | % |   | .30 | % |
|                                                          |   |                                                |                      |   |   |   |   |
| Expected                volatility (2)                        |   |                                                | 32.38                     | % |   | 48.00 | % |
|                                                          |   |                                                |                      |   |   |   |   |
| Risk-free                interest rate (3)                    |   |                                                | 5.08                      | % |   | 4.00 | % |
|                                                          |   |                                                |                      |   |   |   |   |
| Expected                terms (4)                             |   |                                                | 8.11                years |   |   | 6.40                years |   |
|                                                          |   |                                                |                      |   |   |   |   |
| Weighted                average fair value of options granted |   | $                                                   | 8.65                      |   | $ | 7.23 |   |

| (1)    | The                dividend yield is based on our historical experience and future                expectation of dividend payouts.                                                                                            |
|--------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   |                                                                                                                                                                                                                          |
| (2)    | We                analyzed the volatility of our stock using historical data from January                1,                2003 through the end of the most recent period to estimate the expected                volatility. |

----

INDEX

| (3)    | The                    risk-free interest rate assumption is based on U.S. Treasury                    securities at                    a constant maturity with a maturity period that most closely                    resembles the                    expected term of the stock option award.                     |
|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   |                                                                                                                                                                                                                                                                                                                  |
| (4)    | The                    expected terms of employee stock options represents the weighted-average                    period the stock options are expected to remain outstanding and                    has been                    determined based on an analysis of historical exercise                    behavior. |

|                                     |   | **Option                Totals** |      | **Weighted                Average Exercise****Price                Per Share ($)** |   |
|------------------------------------------|--------|----------------------------------|-----------|------------------------------------------------------------------------------------|--------|
|                                     |   |                             |      |                                                                               |   |
| Outstanding                12/31/2005    |   |                             | 4,562,511 |                                                                               |   | 10.68 |   |
|                                     |   |                             |      |                                                                               |   |   |   |
| Granted                                  |   |                             | 780,960   |                                                                               |   | 18.70 |   |
|                                     |   |                             |      |                                                                               |   |   |   |
| Exercised                                |   |                             | (196,136  | )                                                                                  |   | 6.00 |   |
|                                     |   |                             |      |                                                                               |   |   |   |
| Forfeited                                |   |                             | (149,338  | )                                                                                  |   | 10.95 |   |
|                                     |   |                             |      |                                                                               |   |   |   |
| Outstanding                as of 6/30/06 |   |                             | 4,997,997 |                                                                               |   | 12.26 |   |

|                                                |   | **Unvested                  Option Totals** |      | **Weighted                  Average Exercise****Price                  Per Share ($)** |   |
|-----------------------------------------------------|--------|---------------------------------------------|-----------|----------------------------------------------------------------------------------------|--------|
|                                                |   |                                        |      |                                                                                   |   |
| Unvested                  Outstanding 3/31/06       |   |                                        | 2,684,259 |                                                                                   |   | 11.64 |   |
|                                                |   |                                        |      |                                                                                   |   |   |   |
| Granted                                             |   |                                        | 768,960   |                                                                                   |   | 18.67 |   |
|                                                |   |                                        |      |                                                                                   |   |   |   |
| Vested                                              |   |                                        | (178,079  | )                                                                                      |   | 9.48 |   |
|                                                |   |                                        |      |                                                                                   |   |   |   |
| Forfeited                                           |   |                                        | (13,839   | )                                                                                      |   | 12.87 |   |
|                                                |   |                                        |      |                                                                                   |   |   |   |
| Unvested                  Outstanding as of 6/30/06 |   |                                        | 3,261,301 |                                                                                   |   | 13.42 |   |

----

INDEX

| **Range                of****Exercise                Prices****($)** |   | **Number****Outstanding**       |   | **Weighted                Avg.****Contractual****Years****Remaining** |   | **Weighted                Avg.****Exercise                Price****Per                Share****($)**                                |   | **Number****V****ested                and****Exercisable** |   | **Weighted                Avg.****Exercise                Price****Per                Share for****Vested                and****Exercisable                ($)** |
|----------------------------------------------------------------------|--------|---------------------------------|--------|-----------------------------------------------------------------------|--------|-------------------------------------------------------------------------------------------------------------------------------------|--------|------------------------------------------------------------|--------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                 |   |                            |   |                                                                  |   |                                                                                                                                |   |                                                       |   |                                                                                                                                                             |
| 0.00                - 10.00                                          |   |                  1,230,739 |   | 4.56                                                                  |   | 5.19                       |   | 854,994                                                    |   | 4.67                                                    |
| 10.01                - 15.00                                         |   |                  1,921,972 |   | 7.83                                                                  |   | 12.12                      |   | 91,201                                                     |   | 12.05                                                   |
| 15.01                - 25.00                                         |   |                  1,845,286 |   | 9.44                                                                  |   | 17.11                      |   | 790,501                                                    |   | 15.70                                                   |
| Overall                Total                                         |   |                  4,997,997 |   | 7.62                                                                  |   | 12.26                      |   | 1,736,696                                                  |   | 10.08                                                   |

**Note      3.**
**Earnings      Per Share (in thousands, except per share data)**

|                                                                                                           |   | Three                Months EndedJune                30, |   | Six                Months EndedJune                30, |   |
|----------------------------------------------------------------------------------------------------------------|--------|----------------------------------------------------------|--------|--------------------------------------------------------|--------|
|                                                                                                           |   |                                                     |   |                                                   |   |   |   |   |   |
|                                                                                                           |   | 2006                                                     |   | 2005                                                   |   | 2006 |   | 2005 |   |
|                                                                                                           |   |                                                     |   |                                                   |   |   |   |   |   |
| Weighted                average common shares outstanding                - basic                               |   |                                                     | 85,830 |                                                   |   | 85,223 |   |   | 85,788 |   |   | 85,172 |   |
|                                                                                                           |   |                                                     |   |                                                   |   |   |   |   |   |   |   |   |   |
| Effect                of stock options                                                                         |   |                                                     | 1,283  |                                                   |   | 1,743 |   |   | 1,353 |   |   | 1,848 |   |
|                                                                                                           |   |                                                     |   |                                                   |   |   |   |   |   |   |   |   |   |
| Weighted                average common share and common                share equivalents outstanding - diluted |   |                                                     | 87,113 |                                                   |   | 86,966 |   |   | 87,141 |   |   | 87,020 |   |
|                                                                                                           |   |                                                     |   |                                                   |   |   |   |   |   |   |   |   |   |
| Net                income                                                                                      |   | $                                                        | 18,121 |                                                   | $      | 14,957 |   | $ | 33,953 |   | $ | 27,715 |   |
|                                                                                                           |   |                                                     |   |                                                   |   |   |   |   |   |   |   |   |   |
| Earnings                per common share and common share                equivalent                            |   |                                                     |   |                                                   |   |   |   |   |   |   |   |   |   |
| Basic                                                                                                          |   | $                                                        | 0.21   |                                                   | $      | 0.18 |   | $ | 0.40 |   | $ | 0.33 |   |
| Diluted                                                                                                        |   | $                                                        | 0.21   |                                                   | $      | 0.17 |   | $ | 0.39 |   | $ | 0.32 |   |
|                                                                                                           |   |                                                     |   |                                                   |   |   |   |   |   |   |   |   |   |

----

INDEX

**Note      4.**
**Segment      Information**

**Note      5.**
**    New      Accounting Pronouncements**

**Note      6.**
**    Commitments      and Contingencies**

**Note      7.**
**    Dividends**

**Note      8.**
**Other      Assets**

----

INDEX

**Note      9.**
**Assets      Held for Sale**

**Note      10.**
**    Acquisition**

**Item      2.**
**Management's      Discussion and Analysis of Financial Condition and Results of      Operation**

**Cautionary      Note Regarding Forward-Looking Statements**

*Except      for certain historical information contained herein, this report contains      forward-looking statements that involve risks, assumptions, and uncertainties      which are difficult to predict. All statements, other than statements of      historical fact, are statements that could be deemed forward-looking statements,      including without limitation: any projections of earnings, revenues, or other      financial items; any statement of plans, strategies, and objectives of      management for future operations; any statements concerning proposed new      services or developments; any statements regarding future economic conditions      or      performance; and any statements of belief and any statement of assumptions      underlying any of the foregoing. Words such as "believe," "may," "could,"      "expects," "hopes," "anticipates," and "likely," and variations of these words,      or similar expressions, are intended to identify such forward-looking      statements. Actual events or results could differ materially from those      discussed in forward-looking statements. Factors that could cause or contribute      to such differences include, but are not limited to, those discussed in the      section entitled "Item      1A. Risk Factors**,"      set forth below. We do not assume, and specifically disclaim, any obligation      to      update any forward-looking statement contained in this report.*

**Introduction**

***Business      Overview***

----

INDEX

***Operating      and Growth Strategy***

***Revenue      and Expenses***

***Recent      Results of Operations and Quarter-End Financial      Condition***

| · | Revenue,                before fuel surcharge, increased 17.2%, to $140.4 million from $119.7                million; |
|--------|-----------------------------------------------------------------------------------------------------------------------|
|   |                                                                                                                  |
| · | Net                income increased 21.2%, to $18.1 million from $15.0 million;                and                    |
|   |                                                                                                                  |
| · | Net                income per diluted share increased 23.5%, to $0.21 from                $0.17.                      |

----

INDEX

**Results      of Operations**

|                                             |   | (Total                revenue)**Three-Month****Period                Ended****June                30,** |   | (Revenue                before fuel surcharge)**Three-Month****Period                Ended****June                30,** |   | (Total                revenue)**Six-Month****Period                Ended****June                30,** |   | (Revenue                before fuel surcharge)**Six-Month****Period                Ended****June                30,** |   |
|--------------------------------------------------|--------|---------------------------------------------------------------------------------------------------------|--------|-------------------------------------------------------------------------------------------------------------------------|--------|-------------------------------------------------------------------------------------------------------|--------|-----------------------------------------------------------------------------------------------------------------------|--------|
|                                             |   |                                                                                                    |   |                                                                                                                    |   |                                                                                                  |   |                                                                                                                  |   |   |   |   |   |   |   |   |   |
|                                             |   | **2006**                                                                                                |   | **2005**                                                                                                                |   | **2006**                                                                                              |   | **2005**                                                                                                              |   | **2006** |   | **2005** |   | **2006** |   | **2005** |   |
|                                             |   |                                                                                                    |   |                                                                                                                    |   |                                                                                                  |   |                                                                                                                  |   |   |   |   |   |   |   |   |   |
| Revenue                                          |   |                                                                                                    | 100.0  | %                                                                                                                       |   | 100.0                                                                                                 | %      |                                                                                                                  | 100.0  | % |   | 100.0 | % |   | 100.0 | % |   | 100.0 | % |   | 100.0 | % |   | 100.0 | % |
|                                             |   |                                                                                                    |   |                                                                                                                    |   |                                                                                                  |   |                                                                                                                  |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Operating                expenses:               |   |                                                                                                    |   |                                                                                                                    |   |                                                                                                  |   |                                                                                                                  |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Salaries,                wages and benefits      |   |                                                                                                    | 28.9   |                                                                                                                    |   | 29.3                                                                                                  |   |                                                                                                                  | 34.0   |   |   | 32.7 |   |   | 28.9 |   |   | 29.7 |   |   | 33.8 |   |   | 33.0 |   |
| Fuel                                             |   |                                                                                                    | 26.1   |                                                                                                                    |   | 22.6                                                                                                  |   |                                                                                                                  | 12.7   |   |   | 13.4 |   |   | 25.2 |   |   | 21.9 |   |   | 12.7 |   |   | 13.3 |   |
| Operations                and maintenance        |   |                                                                                                    | 5.0    |                                                                                                                    |   | 6.1                                                                                                   |   |                                                                                                                  | 5.9    |   |   | 6.8 |   |   | 5.6 |   |   | 6.2 |   |   | 6.6 |   |   | 6.8 |   |
| Insurance                and claims              |   |                                                                                                    | 3.7    |                                                                                                                    |   | 4.4                                                                                                   |   |                                                                                                                  | 4.4    |   |   | 5.0 |   |   | 3.8 |   |   | 4.8 |   |   | 4.4 |   |   | 5.3 |   |
| Operating                taxes and licenses      |   |                                                                                                    | 2.0    |                                                                                                                    |   | 2.2                                                                                                   |   |                                                                                                                  | 2.4    |   |   | 2.5 |   |   | 2.1 |   |   | 2.3 |   |   | 2.4 |   |   | 2.6 |   |
| Communications                                   |   |                                                                                                    | 0.9    |                                                                                                                    |   | 0.7                                                                                                   |   |                                                                                                                  | 1.0    |   |   | 0.8 |   |   | 0.9 |   |   | 0.8 |   |   | 1.0 |   |   | 0.9 |   |
| Depreciation                and amortization     |   |                                                                                                    | 9.0    |                                                                                                                    |   | 9.6                                                                                                   |   |                                                                                                                  | 10.7   |   |   | 10.7 |   |   | 9.4 |   |   | 9.8 |   |   | 10.9 |   |   | 10.9 |   |
| Lease                expense - revenue equipment |   |                                                                                                    | 0.1    |                                                                                                                    |   | 0.0                                                                                                   |   |                                                                                                                  | 0.1    |   |   | 0.0 |   |   | 0.1 |   |   | 0.0 |   |   | 0.1 |   |   | 0.0 |   |
| Purchased                transportation          |   |                                                                                                    | 5.8    |                                                                                                                    |   | 5.3                                                                                                   |   |                                                                                                                  | 7.0    |   |   | 6.0 |   |   | 5.6 |   |   | 5.3 |   |   | 6.6 |   |   | 5.9 |   |
| Miscellaneous                operating expenses  |   |                                                                                                    | 0.4    |                                                                                                                    |   | 1.3                                                                                                   |   |                                                                                                                  | 0.5    |   |   | 1.4 |   |   | 0.6 |   |   | 1.3 |   |   | 0.7 |   |   | 1.4 |   |
| Total                operating expenses          |   |                                                                                                    | 81.9   |                                                                                                                    |   | 81.5                                                                                                  |   |                                                                                                                  | 78.7   |   |   | 79.3 |   |   | 82.2 |   |   | 82.1 |   |   | 79.2 |   |   | 80.1 |   |
| Income                from operations            |   |                                                                                                    | 18.1   |                                                                                                                    |   | 18.5                                                                                                  |   |                                                                                                                  | 21.3   |   |   | 20.7 |   |   | 17.8 |   |   | 17.9 |   |   | 20.8 |   |   | 19.9 |   |
| Net                interest income               |   |                                                                                                    | 0.1    |                                                                                                                    |   | 0.1                                                                                                   |   |                                                                                                                  | 0.2    |   |   | 0.1 |   |   | 0.2 |   |   | 0.1 |   |   | 0.2 |   |   | 0.1 |   |
| Income                before income taxes        |   |                                                                                                    | 18.2   |                                                                                                                    |   | 18.6                                                                                                  |   |                                                                                                                  | 21.5   |   |   | 20.8 |   |   | 18.0 |   |   | 18.0 |   |   | 21.0 |   |   | 20.0 |   |
| Income                taxes                      |   |                                                                                                    | 7.3    |                                                                                                                    |   | 7.5                                                                                                   |   |                                                                                                                  | 8.6    |   |   | 8.3 |   |   | 7.2 |   |   | 7.2 |   |   | 8.4 |   |   | 8.0 |   |
| Net                income                        |   |                                                                                                    | 10.9   | %                                                                                                                       |   | 11.1                                                                                                  | %      |                                                                                                                  | 12.9   | % |   | 12.5 | % |   | 10.8 | % |   | 10.8 | % |   | 12.6 | % |   | 12.0 | % |
|                                             |   |                                                                                                    |   |                                                                                                                    |   |                                                                                                  |   |                                                                                                                  |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| ____________________________                     |   |                                                                                                    |   |                                                                                                                    |   |                                                                                                  |   |                                                                                                                  |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |

----

INDEX

**Comparison      of Six Months and Three Months Ended June 30, 2006 to Six Months and Three      Months Ended June 30, 2005**

----

INDEX

----

INDEX

**Liquidity      and Capital Resources**

----

INDEX

**Off-Balance      Sheet Transactions**

**Critical      Accounting Policies and Estimates**

**Revenue      Recognition.**

----

INDEX

**Depreciation.**

**Claims      Accrual**
***.***

**Accounting      for Income Taxes.**

**Item      3.**
**Quantitative      and Qualitative Disclosures About Market Risk**

----

INDEX

**Interest      Rate Risk **

**Commodity      Price Risk **

**Item      4.**
**    Controls      and      Procedures**

----

INDEX

**PART      II - OTHER INFORMATION**

**Item      1.**
**Legal      Proceedings**

**Item      1A.           **
**Risk      Factors **

**Item      2.**
**Unregistered      Sales of Equity Securities and **
**Use      **
**of      Proceeds**

**Item      3.**
**Defaults      Upon Senior Securities**

**Item      4.**
**    Submission      of      Matters to a Vote of Security Holders **

|                              |   | **Votes                For** |       | **Votes****Withheld** |   |
|-----------------------------------|--------|------------------------------|------------|-----------------------|--------|
|                              |   |                         |       |                  |   |
| Gary                J. Knight     |   |                         | 74,565,800 |                  |   | 208,998 |   |
| G.D.                Madden        |   |                         | 76,092,715 |                  |   | 554,083 |   |
| Kathryn                L. Munro   |   |                         | 69,426,186 |                  |   | 396,842 |   |
| Richard                J. Lehmann |   |                         | 76,249,956 |                  |   | 396,842 |   |

----

INDEX

| For:                             |   |   | 76,598,005 |   |
|----------------------------------|--------|--------|------------|--------|
| Against:                         |   |   | 7,951      |   |
| Abstentions:                     |   |   | 34,842     |   |
| Broker                non-votes: |   |   | 0          |   |

**Item      5.**
**Other      Information**

**Item      6.**
**          Exhibits**

| Exhibit                No. |    | Description                                                                                                                                                                                                                                                      |
|----------------------------|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                       |    |                                                                                                                                                                                                                                                             |
| Exhibit                3   |    | Articles                of Incorporation and Bylaws                                                                                                                                                                                                              |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (3.1)   | Restated                Articles of Incorporation of the Company. (Incorporated by reference                to                Exhibit 3.1 to the Company's Registration Statement on Form S-1.                No                33-83534.)                       |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (3.1.1) | First                Amendment to Restated Articles of Incorporation of the Company.                (Incorporated by reference to Exhibit 3.1.1 to the Company's report                on                Form 10-K for the period ended December 31, 2000.) |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (3.1.2) | Second                Amendment to Restated Articles of Incorporation of the Company.                (Incorporated by reference to Exhibit 3.1.2 to the Company's Registration                Statement on Form S-3 No. 333-72130.)                              |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (3.1.3) | Third                Amendment to Restated Articles of Incorporation of the Company.                (Incorporated by reference to Exhibit 3.1.3 to the Company's Report                on                Form 10-K for the period ended December 31, 2002.)      |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (3.2)   | Restated                Bylaws of the Company. (Incorporated by reference to Exhibit 3.2                to the                Company's Registration Statement on Form S-3 No.                333-72130.)                                                        |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (3.2.1) | First                Amendment to Restated Bylaws of the Company. (Incorporated by reference                to                Exhibit 3.2.1 to the Company's Report on Form 10-K for the period                ended                December 31, 2002.)          |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (3.2.2) | Second                Amendment to Restated Bylaws of the Company. (Incorporated by reference                to                Exhibit 3.2.1 to the Company's Report on Form 8-K dated March 2,                2005 and                filed on March 4, 2005.)  |
|                       |    |                                                                                                                                                                                                                                                             |
| Exhibit                4   |    | Instruments                defining the rights of security holders, including                indentures                                                                                                                                                          |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (4.1)   | Articles                4, 10, and 11 of the Restated Articles of Incorporation of the Company.                (Incorporated by reference to Exhibit 3.1 to this Report on Form                10-Q.)                                                            |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (4.2)   | Sections                2 and 5 of the Restated Bylaws of the Company. (Incorporated by reference                to Exhibit 3.2 to this Report on Form 10-Q.)                                                                                                    |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (4.3)   | Knight                Transportation, Inc. 2003 Stock Option Plan. (Incorporated by reference                from Exhibit 1 to the Company's Proxy Statement filed April 4, 2003                on                Schedule 14A.)                                 |
|                       |    |                                                                                                                                                                                                                                                             |

----

INDEX

|                      | (4.3.1) | First                Amendment to Knight Transportation, Inc. 2003 Stock Option Plan.                (Incorporated by reference to Exhibit 10.10.1 to the Company's Report                of                Form 10-Q for the period ended March 31, 2005.)               |
|---------------------------|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                      |    |                                                                                                                                                                                                                                                                      |
| Exhibit                31 |    | Section                302 Certifications                                                                                                                                                                                                                                 |
|                      |    |                                                                                                                                                                                                                                                                      |
|                      | (31.1)  | Certification                pursuant to Item 601(b)(31) of Regulation S-K, as adopted pursuant                to                Section 302 of the Sarbanes-Oxley Act of 2002, by Kevin P. Knight,                the                Company's Chief Executive Officer.  |
|                      |    |                                                                                                                                                                                                                                                                      |
|                      | (31.2)  | Certification                pursuant to Item 601(b)(31) of Regulation S-K, as adopted pursuant                to                Section 302 of the Sarbanes-Oxley Act of 2002, by David A. Jackson,                the                Company's Chief Financial Officer. |
|                      |    |                                                                                                                                                                                                                                                                      |
| Exhibit                32 |    | Section                906 Certifications                                                                                                                                                                                                                                 |
|                      |    |                                                                                                                                                                                                                                                                      |
|                      | (32.1)  | Certification                pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section                906 of                the Sarbanes-Oxley Act of 2002, by Kevin P Knight, the Company's                Chief                Executive Officer.              |
|                      |    |                                                                                                                                                                                                                                                                      |
|                      | (32.2)  | Certification                pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section                906 of                the Sarbanes-Oxley Act of 2002, by David A. Jackson, the Company's                Chief                Financial Officer.            |

----

INDEX

**SIGNATURES**

|                                |   | KNIGHT                TRANSPORTATION, INC.                                                                                                    |
|-------------------------------------|--------|-----------------------------------------------------------------------------------------------------------------------------------------------|
|                                |   |                                                                                                                                          |
|                                |   |                                                                                                                                          |
|                                |   |                                                                                                                                          |
| Date:                August 8, 2006 | By:    | /s/                Kevin P. Knight                                                                                                            |
|                                |   | Kevin                P. KnightChief                Executive Officer, in his capacity as such and on                behalf of the registrant  |
|                                |   |                                                                                                                                          |
|                                |   |                                                                                                                                          |
|                                |   |                                                                                                                                          |
|                                |   |                                                                                                                                          |
| Date:                August 8, 2006 | By:    | /s/                David A. Jackson                                                                                                           |
|                                |   | David                A. JacksonChief                Financial Officer, in his capacity as such and on                behalf of the registrant |

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INDEX