----

**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 March 31, 2007                                                                                                                                                                                                                   |
|                                                                                                                                                                                                                                                                             |
|                                                             or |
|                                                                                                                                                                                                                                                                             |                                                                                                                                            |
| **o**                                                                                                                                                                                                                                                                            | **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 o | Non-accelerated                filer o |
|------------------------------------------|------------------------------------|----------------------------------------|

oYes  xNo

----

**KNIGHT      TRANSPORTATION, INC.**

**INDEX**

| **PART                I -****FINANCIAL                INFORMATION** | **Page                Number**                                                                                                                          |
|---------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                |                                                                                                                                                    |
| **Item                1.**                                          | **Financial                Statements**                                                                                                                 |   |
|                                                                |                                                                                                                                                    |   |
|                                                                | Condensed                Consolidated Balance Sheets as of March 31, 2007 and                December 31, 2006 (Unaudited)                              | 3 |
|                                                                |                                                                                                                                                    |   |
|                                                                | Condensed                Consolidated Statements of Income for the three months ended March                31,                2007 and 2006 (Unaudited) | 5 |
|                                                                |                                                                                                                                                    |   |
|                                                                | Condensed                Consolidated Statements of Cash Flows for the three months                ended March 31, 2007 and 2006 (Unaudited)            | 6 |
|                                                                |                                                                                                                                                    |   |
|                                                                | Notes                to Condensed Consolidated Financial Statements (Unaudited)                                                                         | 8 |
|                                                                |                                                                                                                                                    |   |
| **Item                2.**                                          | **Management's                Discussion and Analysis of Financial Condition****and                Results of Operations**                              | 12 |
|                                                                |                                                                                                                                                    |   |
| **Item                3.**                                          | **Quantitative                and Qualitative Disclosures About Market Risk**                                                                           | 19 |
|                                                                |                                                                                                                                                    |   |
| **Item                4.**                                          | **Controls                and Procedures**                                                                                                              | 19 |
|                                                                |                                                                                                                                                    |   |
| **Part                II -****OTHER                INFORMATION**    |                                                                                                                                                    |
|                                                                |                                                                                                                                                    |   |
| **Item                1.**                                          | **Legal                Proceedings**                                                                                                                    | 20 |
|                                                                |                                                                                                                                                    |   |
| **Item                1A.**                                         | **Risk                Factors**                                                                                                                         | 20 |
|                                                                |                                                                                                                                                    |   |
| **Item                2.**                                          | **Unregistered                Sales of Equity Securities and Use of Proceeds**                                                                          | 20 |
|                                                                |                                                                                                                                                    |   |
| **Item                3.**                                          | **Defaults                Upon Senior Securities**                                                                                                      | 20 |
|                                                                |                                                                                                                                                    |   |
| **Item                4.**                                          | **Submission                of Matters to a Vote of Security Holders**                                                                                  | 20 |
|                                                                |                                                                                                                                                    |   |
| **Item                5.**                                          | **Other                Information**                                                                                                                    | 21 |
|                                                                |                                                                                                                                                    |   |
| **Item                6.**                                          | **Exhibits**                                                                                                                                            | 21 |
|                                                                |                                                                                                                                                    |   |
| **Signatures**                                                      |                                                                                                                                                    | 23 |

----

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

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Balance Sheets****(unaudited)****As                of March 31, 2007 and December 31, 2006****(In                thousands)** |   |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                                                                 |   |
|                                                                                                                                                                                                                                 |   | March                31, 2007 |   | December                31, 2006 |   |
| ASSETS                                                                                                                                                                                                                               |   |   |   |   |   |
| Current                Assets:                                                                                                                                                                                                       |   |   |   |   |   |
| Cash                and cash equivalents                                                                                                                                                                                             |   | $ | 20,150 |   | $ | 1,582 |   |
| Accounts                receivable, net                                                                                                                                                                                              |   |   | 82,206 |   |   | 85,350 |   |
| Notes                receivable, net                                                                                                                                                                                                 |   |   | 267 |   |   | 341 |   |
| Other                current assets                                                                                                                                                                                                  |   |   | 15,384 |   |   | 16,613 |   |
| Prepaid                expenses                                                                                                                                                                                                      |   |   | 9,126 |   |   | 8,342 |   |
| Deferred                tax asset                                                                                                                                                                                                    |   |   | 9,117 |   |   | 8,759 |   |
| Total                current assets                                                                                                                                                                                                  |   |   | 136,250 |   |   | 120,987 |   |
|                                                                                                                                                                                                                                 |   |   |   |   |   |   |   |
| Property                and Equipment:                                                                                                                                                                                               |   |   |   |   |   |   |   |
| Land                and improvements                                                                                                                                                                                                 |   |   | 21,803 |   |   | 21,778 |   |
| Buildings                and improvements                                                                                                                                                                                            |   |   | 41,809 |   |   | 38,656 |   |
| Furniture                and fixtures                                                                                                                                                                                                |   |   | 6,704 |   |   | 6,410 |   |
| Shop                and service equipment                                                                                                                                                                                            |   |   | 3,788 |   |   | 3,738 |   |
| Revenue                equipment                                                                                                                                                                                                     |   |   | 495,665 |   |   | 496,117 |   |
| Leasehold                improvements                                                                                                                                                                                                |   |   | 578 |   |   | 516 |   |
|                                                                                                                                                                                                                                 |   |   | 570,347 |   |   | 567,215 |   |
| Less:                Accumulated depreciation and                amortization                                                                                                                                                        |   |   | (136,654 | ) |   | (133,387 | ) |
| Property                and equipment, net                                                                                                                                                                                           |   |   | 433,693 |   |   | 433,828 |   |
| Notes                receivable - long-term                                                                                                                                                                                          |   |   | 308 |   |   | 348 |   |
| Goodwill                                                                                                                                                                                                                             |   |   | 10,268 |   |   | 10,256 |   |
| Intangible                assets, net                                                                                                                                                                                                |   |   | 284 |   |   | 300 |   |
| Other                assets & restricted cash                                                                                                                                                                                    |   |   | 4,836 |   |   | 4,500 |   |
|          Total                assets                                                                                                                                                    |   | $ | 585,639 |   | $ | 570,219 |   |

----

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Balance Sheets (unaudited) (continued)****As                of March 31, 2007 and December 31, 2006****(In                thousands, except par values)**                                                            |   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                                                                                                                                                        |   |   |   |   |   |
|                                                                                                                                                                                                                                                                                                                        |   | March                31, 2007 |   | December                31, 2006 |   |
| LIABILITIES                AND SHAREHOLDERS' EQUITY                                                                                                                                                                                                                                                                         |   |   |   |   |   |
| Current                Liabilities:                                                                                                                                                                                                                                                                                         |   |   |   |   |   |
| Accounts                payable                                                                                                                                                                                                                                                                                             |   | $ | 2,864 |   | $ | 13,077 |   |
| Accrued                payroll                                                                                                                                                                                                                                                                                              |   |   | 7,987 |   |   | 7,411 |   |
| Accrued                liabilities                                                                                                                                                                                                                                                                                          |   |   | 22,991 |   |   | 15,184 |   |
| Claims                accrual                                                                                                                                                                                                                                                                                               |   |   | 25,371 |   |   | 25,926 |   |
| Total                current liabilities                                                                                                                                                                                                                                                                                    |   |   | 59,213 |   |   | 61,598 |   |
| Deferred                tax liabilities                                                                                                                                                                                                                                                                                     |   |   | 84,240 |   |   | 82,526 |   |
| Total                liabilities                                                                                                                                                                                                                                                                                            |   |   | 143,453 |   |   | 144,124 |   |
|                                                                                                                                                                                                                                                                                                                        |   |   |   |   |   |   |   |
| 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;                                 86,226                and 85,666 shares issued and outstandingat                March 31, 2007 and December 31, 2006, respectively |   |   | 862 |   |   | 861 |   |
| Additional                paid-in capital                                                                                                                                                                                                                                                                                   |   |   | 95,809 |   |   | 94,220 |   |
| Retained                earnings                                                                                                                                                                                                                                                                                            |   |   | 345,515 |   |   | 331,014 |   |
| Total                shareholders' equity                                                                                                                                                                                                                                                                                   |   |   | 442,186 |   |   | 426,095 |   |
| Total                liabilities and shareholders' equity                                                                                                                                                                                                                                                                   |   | $ | 585,639 |   | $ | 570,219 |   |

----

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Statements of Income (unaudited)****(In                thousands, except per share data)** |   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                              |   |   |   |
|                                                                                                                                                                                              |   | Three                Months Ended March                31, |   |
|                                                                                                                                                                                              |   | 2007 |   | 2006 |   |
| REVENUE:                                                                                                                                                                                          |   |   |   |   |   |
| Revenue,                before fuel surcharge                                                                                                                                                     |   | $ | 144,825 |   | $ | 129,339 |   |
| Fuel                surcharge                                                                                                                                                                     |   |   | 21,709 |   |   | 19,713 |   |
| Total                revenue                                                                                                                                                                      |   |   | 166,534 |   |   | 149,052 |   |
| OPERATING                EXPENSES:                                                                                                                                                                |   |   |   |   |   |   |   |
| Salaries,                wages and benefits                                                                                                                                                       |   |   | 48,840 |   |   | 43,201 |   |
| Fuel                                                                                                                                                                                              |   |   | 39,634 |   |   | 36,022 |   |
| Operations                and maintenance                                                                                                                                                         |   |   | 9,272 |   |   | 9,427 |   |
| Insurance                and claims                                                                                                                                                               |   |   | 8,006 |   |   | 5,754 |   |
| Operating                taxes and licenses                                                                                                                                                       |   |   | 3,557 |   |   | 3,251 |   |
| Communications                                                                                                                                                                                    |   |   | 1,418 |   |   | 1,310 |   |
| Depreciation                and amortization                                                                                                                                                      |   |   | 15,931 |   |   | 14,600 |   |
| Lease                expense - revenue equipment                                                                                                                                                  |   |   | 106 |   |   | 109 |   |
| Purchased                transportation                                                                                                                                                           |   |   | 10,732 |   |   | 7,907 |   |
| Miscellaneous                operating expenses                                                                                                                                                   |   |   | 1,784 |   |   | 1,373 |   |
| Total                operating expenses                                                                                                                                                           |   |   | 139,280 |   |   | 122,954 |   |
|                                                                                                                                                                                              |   |   |   |   |   |   |   |
| Income                from operations                                                                                                                                                             |   |   | 27,254 |   |   | 26,098 |   |
|                                                                                                                                                                                              |   |   |   |   |   |   |   |
| Interest                income                                                                                                                                                                    |   |   | 182 |   |   | 284 |   |
| Other                income                                                                                                                                                                       |   |   | 188 |   |   | - |   |
| Income                before income taxes                                                                                                                                                         |   |   | 27,624 |   |   | 26,382 |   |
|                                                                                                                                                                                              |   |   |   |   |   |   |   |
| Income                taxes                                                                                                                                                                       |   |   | (11,005 | ) |   | (10,550 | ) |
|                                                                                                                                                                                              |   |   |   |   |   |   |   |
| Net                income                                                                                                                                                                         |   | $ | 16,619 |   | $ | 15,832 |   |
|                                                                                                                                                                                              |   |   |   |   |   |   |   |
| Earnings                per common share and common share equivalent:                                                                                                                             |   |   |   |   |   |   |   |
| Basic                                                                                                                                                                                             |   | $ | 0.19 |   | $ | 0.18 |   |
| Diluted                                                                                                                                                                                           |   | $ | 0.19 |   | $ | 0.18 |   |
|                                                                                                                                                                                              |   |   |   |   |   |   |   |
| Weighted                average number of common shares and common share equivalents                outstanding:                                                                                  |   |   |   |   |   |   |   |
| Basic                                                                                                                                                                                             |   |   | 86,173 |   |   | 85,752 |   |
| Diluted                                                                                                                                                                                           |   |   | 87,167 |   |   | 87,260 |   |

----

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Statements of Cash Flows (unaudited)****(In                thousands)** |   |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                           |   |   |   |
|                                                                                                                                                                           |   | Three                Months EndedMarch                31, |   |
|                                                                                                                                                                           |   | 2007 |   | 2006 |   |
| CASH                FLOWS FROM OPERATING ACTIVITIES:                                                                                                                           |   |   |   |   |   |
|                                                                                                                                                                           |   |   |   |   |   |
| Net                income                                                                                                                                                      |   | $ | 16,619 |   | $ | 15,832 |   |
| Adjustments                to reconcile net income to net cash provided byoperating                activities:                                                                 |   |   |   |   |   |   |   |
| Depreciation                and amortization                                                                                                                                   |   |   | 15,931 |   |   | 14,600 |   |
| Gain                on sales of equipment                                                                                                                                      |   |   | (1,450 | ) |   | (1,849 | ) |
| Earn-out                on sold investment                                                                                                                                     |   |   | (188 | ) |   | - |   |
| Non-cash                compensation expense for issuance of stock tocertain                members of board of directors                                                      |   |   | 39 |   |   | 33 |   |
| Provision                (benefit) for allowance for doubtful accounts                                                                                                         |   |   | 306 |   |   | (156 | ) |
| Excess                tax benefits related to stock-based compensation                                                                                                         |   |   | (230 | ) |   | (430 | ) |
| Stock                option expense                                                                                                                                            |   |   | 652 |   |   | 675 |   |
| Deferred                income taxes                                                                                                                                           |   |   | 1,516 |   |   | 1,597 |   |
| Changes                in assets and liabilities:                                                                                                                              |   |   |   |   |   |   |   |
| (Increase)                in short-term investments                                                                                                                            |   |   | - |   |   | (647 | ) |
| Decrease                in trade receivables                                                                                                                                   |   |   | 2,838 |   |   | 11,079 |   |
| Decrease                (Increase) in other current assets                                                                                                                     |   |   | 154 |   |   | (189 | ) |
| (Increase)                in prepaid expenses                                                                                                                                  |   |   | (784 | ) |   | (1,451 | ) |
| (Increase)                in other assets and restricted assets                                                                                                                |   |   | (320 | ) |   | (52 | ) |
| (Decrease)                in accounts payable                                                                                                                                  |   |   | (4,550 | ) |   | (23 | ) |
| Increase                in accrued liabilities, claims accrual and other                                                                                                       |   |   | 7,503 |   |   | 260 |   |
|                                                                                                                                                                           |   |   |   |   |   |   |   |
| Net                cash provided by operating activities                                                                                                                       |   |   | 38,036 |   |   | 39,279 |   |
|                                                                                                                                                                           |   |   |   |   |   |   |   |
| CASH                FLOW FROM INVESTING ACTIVITIES:                                                                                                                            |   |   |   |   |   |   |   |
|                                                                                                                                                                           |   |   |   |   |   |   |   |
| Purchase                of property and equipment                                                                                                                              |   |   | (31,716 | ) |   | (36,487 | ) |
| Proceeds                from sales of equipment                                                                                                                                |   |   | 12,781 |   |   | 9,319 |   |
| Decrease                (Increase) in notes receivable                                                                                                                         |   |   | 115 |   |   | (35 | ) |
| Acquisition-related                contingent payment                                                                                                                          |   |   | (12 | ) |   | (320 | ) |
| Proceeds                from investment earn-out                                                                                                                               |   |   | 188 |   |   | - |   |
| Increase                in restricted cash                                                                                                                                     |   |   | - |   |   | 211 |   |
| Transportation                Resource Partners investment                                                                                                                     |   |   | - |   |   | (806 | ) |
|                                                                                                                                                                           |   |   |   |   |   |   |   |
| Net                cash used in investing activities                                                                                                                           |   |   | (18,644 | ) |   | (28,118 | ) |

----

| **KNIGHT                TRANSPORTATION, INC. AND SUBSIDIARIES****Condensed                Consolidated Statements of Cash Flows (unaudited)                (continued)****(In                thousands)** |   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                                      |   |   |   |
|                                                                                                                                                                                                      |   | Three                Months EndedMarch                31, |   |
|                                                                                                                                                                                                      |   | 2007 |   | 2006 |   |
| CASH                FLOW FROM FINANCING ACTIVITIES:                                                                                                                                                       |   |   |   |   |   |
| Dividends                paid                                                                                                                                                                             |   |   | (1,724 | ) |   | (3,432 | ) |
| Excess                tax benefits related to stock-based compensation                                                                                                                                    |   |   | 230 |   |   | 430 |   |
| Proceeds                from exercise of stock options                                                                                                                                                    |   |   | 670 |   |   | 848 |   |
|                                                                                                                                                                                                      |   |   |   |   |   |   |   |
| Net                cash used in financing activities                                                                                                                                                      |   |   | (824 | ) |   | (2,154 | ) |
|                                                                                                                                                                                                      |   |   |   |   |   |   |   |
| NET                INCREASE IN CASH AND CASH EQUIVALENTS                                                                                                                                                  |   |   | 18,568 |   |   | 9,007 |   |
| CASH                AND CASH EQUIVALENTS, beginning of period                                                                                                                                             |   |   | 1,582 |   |   | 18,809 |   |
|                                                                                                                                                                                                      |   |   |   |   |   |   |   |
| CASH                AND CASH EQUIVALENTS, end of period                                                                                                                                                   |   | $ | 20,150 |   | $ | 27,816 |   |
|                                                                                                                                                                                                      |   |   |   |   |   |   |   |
| SUPPLEMENTAL                DISCLOSURES:                                                                                                                                                                  |   |   |   |   |   |   |   |
| Non-cash                investing and financing transactions:                                                                                                                                             |   |   |   |   |   |   |   |
| Equipment                acquired in accounts payable                                                                                                                                                     |   | $ | 1,255 |   | $ | 1,232 |   |
| FIN48                adoption tax liability                                                                                                                                                               |   | $ | 394 |   | $  | - |   |
|                                                                                                                                                                                                      |   |   |   |   |   |   |   |
| Cash                Flow Information:                                                                                                                                                                     |   |   |   |   |   |   |   |
| Income                taxes paid                                                                                                                                                                          |   | $ | 5,073 |   | $ | 5,429 |   |

----

**KNIGHT      TRANSPORTATION, INC. AND SUBSIDIARIES**

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

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

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

|                                                                 |   | Three                Months EndedMarch                31, |   |
|----------------------------------------------------------------------|--------|-----------------------------------------------------------|--------|
|                                                                 |   | 2007                                                      |   | 2006 |   |
| Gross                stock compensation expense (net of forfeitures) |   | $                                                         | 652    |   | $ | 675 |   |
| Income                tax                                            |   |                                                      | ($259  | ) |   | ($270 | ) |
| Net                stock compensation expense after tax              |   | $                                                         | 393    |   | $ | 405 |   |

----

|                                                          |   | Three                Months EndedMarch                31, |                      |
|---------------------------------------------------------------|--------|-----------------------------------------------------------|---------------------------|
|                                                          |   | 2007                                                      |                      | 2006 |   |
| Dividend                yield (1)                             |   |                                                      | .45                       | % |   | .37 | % |
| Expected                volatility (2)                        |   |                                                      | 32.29                     | % |   | 31.86 | % |
| Risk-free                interest rate (3)                    |   |                                                      | 4.5                       | % |   | 4.71 | % |
| Expected                terms (4)                             |   |                                                      | 6.58                years |   |   | 7.35                years |   |
| Weighted                average fair value of options granted |   | $                                                         | 7.90                      |   | $ | 8.80 |   |

| (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.                                                                                                                                                   |
| (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 from                January 1, 2003 through the end of the most recent                period. |

|                                       |   | **Option                Totals** |      | **Weighted                Average Exercise****Price                Per Share ($)** |   |
|--------------------------------------------|--------|----------------------------------|-----------|------------------------------------------------------------------------------------|--------|
| Outstanding                12/31/2006      |   |                             | 4,490,341 |                                                                               |   | 12.57 |   |
| Granted                                    |   |                             | 8,250     |                                                                               |   | 19.65 |   |
| Exercised                                  |   |                             | (113,171  | )                                                                                  |   | 5.92 |   |
| Forfeited                                  |   |                             | (91,040   | )                                                                                  |   | 14.00 |   |
| Outstanding                as of 3/31/2007 |   |                             | 4,294,380 |                                                                               |   | 12.74 |   |

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

|                                                                                                                                               |   | Three                Months EndedMarch                31, |   |
|----------------------------------------------------------------------------------------------------------------------------------------------------|--------|-----------------------------------------------------------|--------|
|                                                                                                                                               |   | 2007                                                      |   | 2006 |   |
| Weighted                average common shares outstanding - basic                                                                                  |   |                                                      | 86,173 |   |   | 85,752 |   |
| Effect                of stock options                                                                                                             |   |                                                      | 994    |   |   | 1,508 |   |
| Weighted                average common share and common share       equivalents                outstanding - diluted |   |                                                      | 87,167 |   |   | 87,260 |   |
| Net                income                                                                                                                          |   | $                                                         | 16,619 |   |   | 15,832 |   |
| Earnings                per common share and common share equivalent                                                                               |   |                                                      |   |   |   |   |   |
| Basic                                                                                                                                              |   | $                                                         | .19    |   | $ | .18 |   |
| Diluted                                                                                                                                            |   | $                                                         | .19    |   | $ | .18 |   |
|                                                                                                                                               |   |                                                      |   |   |   |   |   |

----

|                                          |   | Three                Months EndedMarch                31, |    |
|-----------------------------------------------|--------|-----------------------------------------------------------|---------|
|                                          |   | 2007                                                      |    | 2006 |   |
| Number                of anti-dilutive shares |   |                                                      | 516,350 |   |   | 7,500 |   |

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

**Note      5.**
**Recent**
**Accounting      Pronouncements**

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

----

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

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

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

**Note      10.**
**Acquisitions**

----

**Note      11.  **
**Income      Taxes**

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

**Cautionary      Note Regarding Forward-Looking Statements**

*Except      for certain historical information contained herein, this report      c*
*ontains      "forward-looking statements" within the meaning of Section 21E of the Securities      Exchange Act of 1934, as amended (the "Exchange Act"), and Section 27A of the      Securities Act of 1933, as amended, that involve risks, assumptions, and      uncertainties that 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 revenues, earnings, cash flows, capital      expenditures, or other financial items; any statement of plans, strategies,      and      objectives of management for future operations; any statements concerning      proposed acquisition plans, 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 in our form 10-K for the year ended December 31, 2006, as supplemented      in Part II below. *

*All      such forward-looking statements speak only as of the date of this Form 10-Q.      You      are cautioned not to place undue reliance on such forward-looking statements.      The Company expressly disclaims any obligation or undertaking to release      publicly any updates or revisions to any forward-looking statements contained      herein to reflect any change in the Company's expectations with regard thereto      or any change in the events, conditions, or circumstances on which any such      statement is based.*

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**Introduction**

***Business      Overview***

***Operating      and Growth Strategy***

***Revenue      and Expenses***

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

| · | Revenue,                before fuel surcharge, increased 12.0%, to $144.8 million from $129.3                million; |
|--------|-----------------------------------------------------------------------------------------------------------------------|
|   |                                                                                                                  |
| · | Net                income increased 5.0%, to $16.6 million from $15.8 million;                and                     |
|   |                                                                                                                  |
| · | Net                income per diluted share increased 5.1%, to $0.19 from $0.18.                                      |

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**Results      of Operations**

|                                             |   | **(Total                revenue)***         |   | **(Revenue                before fuel surcharge)*** |   |
|--------------------------------------------------|--------|---------------------------------------------|--------|-----------------------------------------------------|--------|
|                                             |   | Three                Months Ended March 31, |   |
|                                             |   | **2007**                                    |   | **2006**                                            |   | **2007** |   | **2006** |   |
|                                             |   |                                        |   |                                                |   |   |   |   |   |
| Revenue                                          |   |                                        | 100.0  | %                                                   |   | 100.0 | % |   | 100.0 | % |   | 100.0 | % |
| Operating                expenses:               |   |                                        |   |                                                |   |   |   |   |   |   |   |   |   |
| Salaries,                wages and benefits      |   |                                        | 29.3   |                                                |   | 29.0 |   |   | 33.7 |   |   | 33.4 |   |
| Fuel                                             |   |                                        | 23.8   |                                                |   | 24.2 |   |   | 12.4 |   |   | 12.6 |   |
| Operations                and maintenance        |   |                                        | 5.5    |                                                |   | 6.3 |   |   | 6.4 |   |   | 7.3 |   |
| Insurance                and claims              |   |                                        | 4.8    |                                                |   | 3.9 |   |   | 5.5 |   |   | 4.4 |   |
| Operating                taxes and licenses      |   |                                        | 2.1    |                                                |   | 2.2 |   |   | 2.5 |   |   | 2.5 |   |
| Communications                                   |   |                                        | 0.9    |                                                |   | 0.9 |   |   | 1.0 |   |   | 1.0 |   |
| Depreciation                and amortization     |   |                                        | 9.6    |                                                |   | 9.8 |   |   | 11.0 |   |   | 11.3 |   |
| Lease                expense - revenue equipment |   |                                        | 0.1    |                                                |   | 0.1 |   |   | 0.1 |   |   | 0.1 |   |
| Purchased                transportation          |   |                                        | 6.4    |                                                |   | 5.3 |   |   | 7.4 |   |   | 6.1 |   |
| Miscellaneous                operating expenses  |   |                                        | 1.1    |                                                |   | 0.8 |   |   | 1.2 |   |   | 1.1 |   |
| Total                operating expenses          |   |                                        | 83.6   |                                                |   | 82.5 |   |   | 81.2 |   |   | 79.8 |   |
| Income                from operations            |   |                                        | 16.4   |                                                |   | 17.5 |   |   | 18.8 |   |   | 20.2 |   |
| Net                interest and other income     |   |                                        | 0.2    |                                                |   | 0.2 |   |   | 0.3 |   |   | 0.2 |   |
| Income                before income taxes        |   |                                        | 16.6   |                                                |   | 17.7 |   |   | 19.1 |   |   | 20.4 |   |
| Income                taxes                      |   |                                        | 6.6    |                                                |   | 7.1 |   |   | 7.6 |   |   | 8.2 |   |
| Net                income                        |   |                                        | 10.0   | %                                              |   | 10.6 | % |   | 11.5 | %  |   | 12.2 | % |

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**Comparison      of Three Months Ended March 31, 2007 to Three Months Ended March 31,      2006**

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**Liquidity      and Capital Resources**

**Off-Balance      Sheet Transactions**

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**Critical      Accounting Policies and Estimates**

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

**Interest      Rate Risk **

**Commodity      Price Risk **

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

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**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 **

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**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.)  |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (3.2.3) | Fifth                Amendment to Restated Bylaws of the Company. (Incorporated by reference                to                Exhibit 3 to the Company's Report on Form 8-K dated March 28, 2007                and                filed on March 30, 2007.)     |
|                       |    |                                                                                                                                                                                                                                                             |
| 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. Amended and Restated 2003 Stock Option Plan.                (Incorporated by reference to the Company's Definitive Proxy Statement                on                Schedule 14A filed December 1, 2005.)             |
|                       |    |                                                                                                                                                                                                                                                             |
| Exhibit                10  |    | Material                Contracts                                                                                                                                                                                                                                |
|                       |    |                                                                                                                                                                                                                                                             |
|                       | (10.1)* | Second                Modification Agreement to Credit Agreement by and among Knight                Transportation, Inc. and Wells Fargo Bank, N.A., dated March 30,                2007.                                                                        |

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|                      |                            |                                                                                                                                                                                                                                                                      |
|---------------------------|---------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 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.            |
|                      |                            |
|                      | *Filed                herewith. |

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**SIGNATURES**

|                                  |   |   | KNIGHT                TRANSPORTATION, INC.                                                                                                    |
|---------------------------------------|--------|--------|-----------------------------------------------------------------------------------------------------------------------------------------------|
|                                  |   |   |                                                                                                                                          |
|                                  |   |   |                                                                                                                                          |
|                                  |   |   |                                                                                                                                          |
|  Date:              May 10, 2007 |   | By:    |  /s/Kevin              P. Knight                                                                                                         |
|                                  |   |   | Kevin                P. KnightChief                Executive Officer, in his capacity as such and on behalf of the                registrant  |
|                                  |   |   |                                                                                                                                          |
|                                  |   |   |                                                                                                                                          |
|                                  |   |   |                                                                                                                                          |
|                                  |   |   |                                                                                                                                          |
|  Date:              May 10, 2007 |   | 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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