----

| [X]                                                                                                                                                                                                                                                                        | QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------|
|                                                                                                                                                                                                                                                                       |
| For the quarterly period ended June 30, 2009                                                                                                                                                                                                                               |
|                                                                                                                                                                                                                                                                       |
| or                                                                                                                                                                                                                                                                         |
|                                                                                                                                                                                                                                                                       |                                                                                     |
| [  ]                                                                                                                                                                                                                                                             | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 |
|                                                                                                                                                                                                                                                                       |                                                                                     |
| For the transition period from                                       to |

| Arizona                                                                                       | 86-0649974                          |
|-----------------------------------------------------------------------------------------------|-------------------------------------|
| (State or other jurisdiction ofincorporation or organization)                                 | (I.R.S. EmployerIdentification No.) |
|                                                                                          |                                |
| 5601 West Buckeye RoadPhoenix, Arizona85043(Address of Principal Executive Offices)(Zip Code) |
|                                                                                          |                                |
| Registrant's telephone number, including area code:                                           | 602-269-2000                        |

| Large accelerated filer   x           | Accelerated filer   o         |
|-------------------------------------------------|-----------------------------------------|
| Non-accelerated filer     o | Smaller reporting company   o |

o Yes             x No 

----

KNIGHT TRANSPORTATION, INC.

| PART I – FINANCIAL INFORMATION | Page Number                                                                                                     |
|--------------------------------------|-----------------------------------------------------------------------------------------------------------------|
|                                 |                                                                                                            |
| Item 1.                              | Financial Statements                                                                                            |   |
|                                 |                                                                                                            |   |
|                                 | Condensed Consolidated Unaudited Balance Sheets as of June 30, 2009 and December 31, 2008                       | 1 |
|                                 |                                                                                                            |   |
|                                 | Condensed Consolidated Unaudited Statements of Income for the three and six months ended June 30, 2009 and 2008 | 3 |
|                                 |                                                                                                            |   |
|                                 | Condensed Consolidated Unaudited Statements of Cash Flows for the six months ended June 30, 2009 and 2008       | 4 |
|                                 |                                                                                                            |   |
|                                 | Notes to Condensed Consolidated Unaudited Financial Statements                                                  | 6 |
|                                 |                                                                                                            |   |
| Item 2.                         | Management's Discussion and Analysis of Financial Conditionand Results of Operations                            | 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                                                                                               | 24 |
|                                 |                                                                                                            |   |
| Item 6.                              | Exhibits                                                                                                        | 24 |
|                                 |                                                                                                            |   |
| Signatures                           |                                                                                                            |   |

----

Table of Contents

PART I  -  FINANCIAL INFORMATION

| KNIGHT TRANSPORTATION, INC. AND SUBSIDIARIESCondensed Consolidated Unaudited Balance SheetsAs of June 30, 2009 and December 31, 2008(In thousands) |   |
|----------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                               |   |
|                                                                                                                                               |   | June 30,2009 |   |   | December 31,2008 |   |
| ASSETS                                                                                                                                             |   |   |   |   |   |   |
| Current Assets:                                                                                                                                    |   |   |   |   |   |   |
| Cash and cash equivalents                                                                                                                          |   | $ | 22,829 |   |   | $ | 22,027 |   |
| Short-term investment                                                                                                                              |   |   | 56,553 |   |   |   | 31,877 |   |
| Accounts receivable, net                                                                                                                           |   |   | 69,445 |   |   |   | 70,810 |   |
| Notes receivable, net                                                                                                                              |   |   | 1,073 |   |   |   | 159 |   |
| Prepaid expenses                                                                                                                                   |   |   | 7,526 |   |   |   | 7,108 |   |
| Other current assets and assets held for sale                                                                                                      |   |   | 15,406 |   |   |   | 13,258 |   |
| Income tax receivable                                                                                                                              |   |   | - |   |   |   | 774 |   |
| Current deferred tax asset                                                                                                                         |   |   | 7,148 |   |   |   | 6,480 |   |
| Total current assets                                                                                                                               |   |   | 179,980 |   |   |   | 152,493 |   |
|                                                                                                                                               |   |   |   |   |   |   |   |   |
| Property and Equipment:                                                                                                                            |   |   |   |   |   |   |   |   |
| Land and land improvements                                                                                                                         |   |   | 29,547 |   |   |   | 28,556 |   |
| Buildings and improvements                                                                                                                         |   |   | 66,494 |   |   |   | 58,365 |   |
| Furniture and fixtures                                                                                                                             |   |   | 7,435 |   |   |   | 7,472 |   |
| Shop and service equipment                                                                                                                         |   |   | 6,026 |   |   |   | 4,970 |   |
| Revenue equipment                                                                                                                                  |   |   | 550,583 |   |   |   | 558,561 |   |
| Leasehold improvements                                                                                                                             |   |   | 1,691 |   |   |   | 1,185 |   |
|                                                                                                                                               |   |   | 661,776 |   |   |   | 659,109 |   |
| Less:  Accumulated depreciation and amortization                                                                                         |   |   | (192,920 | ) |   |   | (186,881 | ) |
| Property and equipment, net                                                                                                                        |   |   | 468,856 |   |   |   | 472,228 |   |
| Notes receivable – long-term                                                                                                                 |   |   | 2,000 |   |   |   | 674 |   |
| Goodwill                                                                                                                                           |   |   | 10,343 |   |   |   | 10,353 |   |
| Intangible assets, net                                                                                                                             |   |   | 144 |   |   |   | 176 |   |
| Long-term deferred tax assets                                                                                                                      |   |   | - |   |   |   | 5,877 |   |
| Other long-term assets & restricted cash                                                                                                       |   |   | 7,422 |   |   |   | 5,139 |   |
| Total assets                                                                                                                                       |   | $ | 668,745 |   |   | $ | 646,940 |   |

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Table of Contents

| KNIGHT TRANSPORTATION, INC. AND SUBSIDIARIESCondensed Consolidated Unaudited Balance Sheets (continued)As of June 30, 2009 and December 31, 2008(In thousands, except par values)                                                                        |   |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                                                                                                                                     |   |   |   |   |   |   |
|                                                                                                                                                                                                                                                     |   | June 30,2009 |   |   | December 31,2008 |   |
| LIABILITIES AND SHAREHOLDERS' EQUITY                                                                                                                                                                                                                     |   |   |   |   |   |   |
| Current Liabilities:                                                                                                                                                                                                                                     |   |   |   |   |   |   |
| Accounts payable                                                                                                                                                                                                                                         |   | $ | 12,845 |   |   | $ | 6,195 |   |
| Accrued payroll and purchased transportation                                                                                                                                                                                                             |   |   | 9,684 |   |   |   | 7,432 |   |
| Accrued liabilities                                                                                                                                                                                                                                      |   |   | 11,334 |   |   |   | 6,273 |   |
| Claims accrual – current portion                                                                                                                                                                                                                   |   |   | 14,693 |   |   |   | 15,239 |   |
| Total current liabilities                                                                                                                                                                                                                                |   |   | 48,556 |   |   |   | 35,139 |   |
|                                                                                                                                                                                                                                                     |   |   |   |   |   |   |   |   |
| Long-term Liabilities:                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |   |
| Claims accrual – long-term portion                                                                                                                                                                                                                 |   |   | 14,628 |   |   |   | 15,236 |   |
| Deferred tax liabilities                                                                                                                                                                                                                                 |   |   | 106,916 |   |   |   | 112,661 |   |
| Total long-term liabilities                                                                                                                                                                                                                              |   |   | 121,544 |   |   |   | 127,897 |   |
|                                                                                                                                                                                                                                                     |   |   |   |   |   |   |   |   |
| Total liabilities                                                                                                                                                                                                                                        |   |   | 170,100 |   |   |   | 163,036 |   |
|                                                                                                                                                                                                                                                     |   |   |   |   |   |   |   |   |
| 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; 300,000 shares authorized; 83,130 and 83,383 shares issued and outstanding at                June 30, 2009 and December 31, 2008, respectively |   |   | 831 |   |   |   | 834 |   |
| Additional paid-in capital                                                                                                                                                                                                                               |   |   | 111,694 |   |   |   | 108,885 |   |
| Retained earnings                                                                                                                                                                                                                                        |   |   | 386,120 |   |   |   | 374,185 |   |
| Total shareholders' equity                                                                                                                                                                                                                               |   |   | 498,645 |   |   |   | 483,904 |   |
| Total liabilities and shareholders' equity                                                                                                                                                                                                               |   | $ | 668,745 |   |   | $ | 646,940 |   |

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Table of Contents

| KNIGHT TRANSPORTATION, INC. AND SUBSIDIARIESCondensed Consolidated Statements of Income (unaudited)(In thousands, except per share data) |   |
|------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                                     |   |
|                                                                                                                                     |   | Three Months EndedJune 30, |   |   | Six Months EndedJune 30, |   |
|                                                                                                                                     |   | 2009 |   |   | 2008 |   |   | 2009 |   |   | 2008 |   |
| REVENUE:                                                                                                                                 |   |   |   |   |   |   |   |   |   |   |   |   |
| Revenue, before fuel surcharge                                                                                                           |   | $ | 144,261 |   |   | $ | 154,833 |   |   | $ | 277,390 |   |   | $ | 296,135 |   |
| Fuel surcharge                                                                                                                           |   |   | 17,819 |   |   |   | 51,274 |   |   |   | 33,409 |   |   |   | 86,383 |   |
| Total revenue                                                                                                                            |   |   | 162,080 |   |   |   | 206,107 |   |   |   | 310,799 |   |   |   | 382,518 |   |
| OPERATING EXPENSES:                                                                                                                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Salaries, wages and benefits                                                                                                             |   |   | 49,999 |   |   |   | 53,895 |   |   |   | 98,302 |   |   |   | 103,906 |   |
| Fuel                                                                                                                                     |   |   | 33,579 |   |   |   | 72,730 |   |   |   | 62,458 |   |   |   | 126,286 |   |
| Operations and maintenance                                                                                                               |   |   | 10,737 |   |   |   | 10,647 |   |   |   | 20,725 |   |   |   | 19,947 |   |
| Insurance and claims                                                                                                                     |   |   | 5,392 |   |   |   | 7,713 |   |   |   | 10,709 |   |   |   | 14,779 |   |
| Operating taxes and licenses                                                                                                             |   |   | 3,433 |   |   |   | 3,852 |   |   |   | 6,995 |   |   |   | 7,504 |   |
| Communications                                                                                                                           |   |   | 1,350 |   |   |   | 1,473 |   |   |   | 2,822 |   |   |   | 2,888 |   |
| Depreciation and amortization                                                                                                            |   |   | 17,620 |   |   |   | 17,118 |   |   |   | 35,321 |   |   |   | 34,071 |   |
| Lease expense – revenue equipment                                                                                                  |   |   | - |   |   |   | 36 |   |   |   | - |   |   |   | 90 |   |
| Purchased transportation                                                                                                                 |   |   | 15,277 |   |   |   | 14,570 |   |   |   | 25,972 |   |   |   | 27,491 |   |
| Miscellaneous operating expenses                                                                                                         |   |   | 3,907 |   |   |   | 3,350 |   |   |   | 7,261 |   |   |   | 6,107 |   |
| Total operating expenses                                                                                                                 |   |   | 141,294 |   |   |   | 185,384 |   |   |   | 270,565 |   |   |   | 343,069 |   |
|                                                                                                                                     |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Income from operations                                                                                                                   |   |   | 20,786 |   |   |   | 20,723 |   |   |   | 40,234 |   |   |   | 39,449 |   |
|                                                                                                                                     |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Interest income                                                                                                                          |   |   | 349 |   |   |   | 190 |   |   |   | 655 |   |   |   | 445 |   |
| Other income                                                                                                                             |   |   | - |   |   |   | 225 |   |   |   | (21 | ) |   |   | 225 |   |
| Income before income taxes                                                                                                               |   |   | 21,135 |   |   |   | 21,138 |   |   |   | 40,868 |   |   |   | 40,119 |   |
|                                                                                                                                     |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Income taxes                                                                                                                             |   |   | 8,568 |   |   |   | 8,446 |   |   |   | 16,558 |   |   |   | 16,010 |   |
|                                                                                                                                     |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Net income                                                                                                                               |   | $ | 12,567 |   |   | $ | 12,692 |   |   | $ | 24,310 |   |   | $ | 24,109 |   |
|                                                                                                                                     |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Earnings per common share:                                                                                                               |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Basic                                                                                                                                    |   | $ | 0.15 |   |   | $ | 0.15 |   |   | $ | 0.29 |   |   | $ | 0.28 |   |
| Diluted                                                                                                                                  |   | $ | 0.15 |   |   | $ | 0.15 |   |   | $ | 0.29 |   |   | $ | 0.28 |   |
|                                                                                                                                     |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Weighted average number of common shares outstanding:                                                                                    |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Basic                                                                                                                                    |   |   | 83,069 |   |   |   | 85,523 |   |   |   | 83,165 |   |   |   | 85,901 |   |
| Diluted                                                                                                                                  |   |   | 83,518 |   |   |   | 86,104 |   |   |   | 83,507 |   |   |   | 86,427 |   |

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Table of Contents

| KNIGHT TRANSPORTATION, INC. AND SUBSIDIARIESCondensed Consolidated Unaudited Statements of Cash Flows(In thousands) |   |
|---------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                |   |
|                                                                                                                |   | Six Months EndedJune 30, |   |
|                                                                                                                |   | 2009 |   |   |   |   |   | 2008 |   |
| Cash Flows From Operating Activities:                                                                               |   |   |   |   |   |   |   |   |   |
|                                                                                                                |   |   |   |   |   |   |   |   |   |
| Net income                                                                                                          |   | $ | 24,310 |   |   |   |   |   | $ | 24,109 |   |
| Adjustments to reconcile net income to net cash provided by operating activities:                                   |   |   |   |   |   |   |   |   |   |   |   |
| Depreciation and amortization                                                                                       |   |   | 35,321 |   |   |   |   |   |   | 34,071 |   |
| Gain on sales of equipment                                                                                          |   |   | (1,276 | ) |   |   |   |   |   |   | (1,145 | ) |
| Earn-out on sold investment                                                                                         |   |   | - |   |   |   |   |   |   |   | (225 | ) |
| Impairment loss due to fire                                                                                         |   |   | 25 |   |   |   |   |   |   |   | - |   |
| Non-cash compensation expense for issuance of stock to certain members of board of directors                        |   |   | 112 |   |   |   |   |   |   |   | 135 |   |
| Provision for allowance for doubtful accounts                                                                       |   |   | 1,667 |   |   |   |   |   |   |   | 540 |   |
| Excess tax benefits related to stock-based compensation                                                             |   |   | (211 | ) |   |   |   |   |   |   | (283 | ) |
| Stock option expense                                                                                                |   |   | 1,582 |   |   |   |   |   |   |   | 1,555 |   |
| Deferred income taxes                                                                                               |   |   | (536 | ) |   |   |   |   |   |   | 6,814 |   |
| Changes in assets and liabilities:                                                                                  |   |   |   |   |   |   |   |   |   |   |   |   |
| Increase in short-term investments                                                                                  |   |   | (24,676 | ) |   |   |   |   |   |   | (4,082 | ) |
| Decrease (increase) in trade receivables                                                                            |   |   | 89 |   |   |   |   |   |   |   | (11,948 | ) |
| Increase in other current assets                                                                                    |   |   | (215 | ) |   |   |   |   |   |   | (574 | ) |
| (Increase) decrease in prepaid expenses                                                                             |   |   | (418 | ) |   |   |   |   |   |   | 596 |   |
| Decrease (increase) in income tax receivable                                                                        |   |   | 774 |   |   |   |   |   |   |   | (2,359 | ) |
| Decrease (increase) in other assets                                                                                 |   |   | 63 |   |   |   |   |   |   |   | (28 | ) |
| (Decrease) increase in accounts payable                                                                             |   |   | (1,696 | ) |   |   |   |   |   |   | 1,917 |   |
| Increase in accrued liabilities and claims accrual                                                                  |   |   | 6,399 |   |   |   |   |   |   |   | 3,972 |   |
|                                                                                                                |   |   |   |   |   |   |   |   |   |   |   |   |
| Net cash provided by operating activities                                                                           |   |   | 41,314 |   |   |   |   |   |   |   | 53,065 |   |
|                                                                                                                |   |   |   |   |   |   |   |   |   |   |   |   |
| Cash Flow From Investing Activities:                                                                                |   |   |   |   |   |   |   |   |   |   |   |   |
|                                                                                                                |   |   |   |   |   |   |   |   |   |   |   |   |
| Purchase of property and equipment                                                                                  |   |   | (46,392 | ) |   |   |   |   |   |   | (54,328 | ) |
| Proceeds from sales of equipment                                                                                    |   |   | 18,524 |   |   |   |   |   |   |   | 23,811 |   |
| Proceeds from insurance claim settlement                                                                            |   |   | 300 |   |   |   |   |   |   |   | - |   |
| Decrease in notes receivable                                                                                        |   |   | 683 |   |   |   |   |   |   |   | 374 |   |
| Restricted cash activity                                                                                            |   |   | (2,228 | ) |   |   |   |   |   |   | - |   |
| Proceeds/earn-out from sale of investment in Concentrek, Inc.                                                       |   |   | - |   |   |   |   |   |   |   | 225 |   |
| Investments in Transportation Resource Partners                                                                     |   |   | (150 | ) |   |   |   |   |   |   | - |   |
| Return of investment in Transportation Resource Partners                                                            |   |   | 43 |   |   |   |   |   |   |   | 10 |   |
|                                                                                                                |   |   |   |   |   |   |   |   |   |   |   |   |
| Net cash used in investing activities                                                                               |   |   | (29,220 | ) |   |   |   |   |   |   | (29,908 | ) |

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Table of Contents

| KNIGHT TRANSPORTATION, INC. AND SUBSIDIARIESCondensed Consolidated Unaudited Statements of Cash Flows (continued)(In thousands) |   |
|---------------------------------------------------------------------------------------------------------------------------------|--------|
|                                                                                                                            |   |   |   |
|                                                                                                                            |   | Six Months EndedJune 30, |   |
|                                                                                                                            |   | 2009 |   |   | 2008 |   |
| Cash Flow From Financing Activities:                                                                                            |   |   |   |   |   |   |
| Dividends paid                                                                                                                  |   |   | (7,479 | ) |   |   | (6,000 | ) |
| Payments to acquire treasury stock                                                                                              |   |   | (4,900 | ) |   |   | (18,084 | ) |
| Excess tax benefits related to stock-based compensation                                                                         |   |   | 211 |   |   |   | 283 |   |
| Proceeds from exercise of stock options                                                                                         |   |   | 876 |   |   |   | 1,331 |   |
|                                                                                                                            |   |   |   |   |   |   |   |   |
| Net cash used in financing activities                                                                                           |   |   | (11,292 | ) |   |   | (22,470 | ) |
|                                                                                                                            |   |   |   |   |   |   |   |   |
|  Net increase in cash and cash equivalents                                                                                 |   |   | 802 |   |   |   | 687 |   |
| Cash and cash equivalents, beginning of period                                                                                  |   |   | 22,027 |   |   |   | 23,688 |   |
|                                                                                                                            |   |   |   |   |   |   |   |   |
| Cash and cash equivalents, end of period                                                                                        |   | $ | 22,829 |   |   | $ | 24,375 |   |
|                                                                                                                            |   |   |   |   |   |   |   |   |
| Supplemental Disclosures:                                                                                                       |   |   |   |   |   |   |   |   |
| Non-cash investing and financing transactions:                                                                                  |   |   |   |   |   |   |   |   |
| Equipment acquired in accounts payable                                                                                          |   | $ | 8,389 |   |   | $ | 715 |   |
| Retirement of treasury stock                                                                                                    |   | $ | 4,900 |   |   | $ | 18,084 |   |
| Transfer from property and equipment to assets held for sale                                                                    |   | $ | 14,518 |   |   | $ | 7,034 |   |
| Financing provided to independent contractors for equipment sold                                                                |   | $ | 3,302 |   |   | $ | 345 |   |
|                                                                                                                            |   |   |   |   |   |   |   |   |
| Cash Flow Information:                                                                                                          |   |   |   |   |   |   |   |   |
| Income taxes paid                                                                                                               |   | $ | 13,859 |   |   | $ | 11,225 |   |

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Table of Contents

KNIGHT TRANSPORTATION, INC. AND SUBSIDIARIES

|                                                 |   | Three Months EndedJune 30, |   |   | Six Months EndedJune 30, |   |
|------------------------------------------------------|--------|----------------------------|--------|--------|--------------------------|--------|
|                                                 |   | (in thousands)             |   |   | (in thousands)           |   |
|                                                 |   | 2009                       |   |   | 2008                     |   |   | 2009 |   |   | 2008 |   |
| Gross stock compensation expense, net of forfeitures |   | $                          | 828    |   |                     | $      | 890 |   |   | $ | 1,582 |   |   | $ | 1,555 |   |
| Income tax                                           |   | $                          | (336   | )      |                     | $      | (356 | ) |   | $ | (641 | ) |   | $ | (621 | ) |
| Net stock compensation expense after tax             |   | $                          | 492    |   |                     | $      | 534 |   |   | $ | 941 |   |   | $ | 934 |   |

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Table of Contents

|                                           |   | Three Months EndedJune 30, |   |
|------------------------------------------------|--------|----------------------------|--------|
|                                           |   | 2009                       |   |   | 2008 |   |
| Dividend yield (1)                             |   |                       | N/A    |   |   |   | .90 | % |
| Expected volatility (2)                        |   |                       | N/A    |   |   |   | 33.83 | % |
| Risk-free interest rate (3)                    |   |                       | N/A    |   |   |   | 3.43 | % |
| Expected terms (4)                             |   |                       | N/A    |   |   | 6.16 years |   |
| Weighted average fair value of options granted |   |                       | N/A    |   |   | $ | 6.18 |   |

| (1) | The dividend yield is based on our historical experience and future expectation of dividend payouts.  We increased our quarterly cash dividend paid to common stock shareholders from $0.04 per share to $0.05 per share in the second quarter 2009.  The dividend yield for the three month period ended June 30, 2009 wouldhave increased accordingly had we granted options during the period. |
|-----|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| (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 ExercisePrice Per Share ($) |   |
|------------------------------|--------|---------------|-----------|--------|----------------------------------------------|--------|
| Outstanding 12/31/2008       |   |          | 4,993,691 |   |                                         |   | 14.69 |   |
| Granted                      |   |          | 12,500    |   |                                         |   | 13.31 |   |
| Exercised                    |   |          | (129,831  | )      |                                         |   | 6.74 |   |
| Forfeited                    |   |          | (180,445  | )      |                                         |   | 14.78 |   |
| Outstanding as of 06/30/2009 |   |          | 4,695,915 |   |                                         |   | 14.87 |   |

|                                                       |   | Three Months EndedJune 30, |   |   | Six Months EndedJune 30, |   |
|------------------------------------------------------------|--------|----------------------------|--------|--------|--------------------------|--------|
|                                                       |   | 2009                       |   |   | 2008                     |   |   | 2009 |   |   | 2008 |   |
| Weighted average common shares outstanding – basic   |   |                       | 83,069 |   |                     |   | 85,523 |   |   |   | 83,165 |   |   |   | 85,901 |   |
| Effect of stock options                                    |   |                       | 449    |   |                     |   | 581 |   |   |   | 342 |   |   |   | 526 |   |
| Weighted average common shares outstanding – diluted |   |                       | 83,518 |   |                     |   | 86,104 |   |   |   | 83,507 |   |   |   | 86,427 |   |
|                                                       |   |                       |   |   |                     |   |   |   |   |   |   |   |   |   |   |   |
| Net income                                                 |   | $                          | 12,567 |   |                     | $      | 12,692 |   |   | $ | 24,310 |   |   | $ | 24,109 |   |
| Earnings per common share                                  |   |                       |   |   |                     |   |   |   |   |   |   |   |   |   |   |   |
| Basic                                                      |   | $                          | 0.15   |   |                     | $      | 0.15 |   |   | $ | 0.29 |   |   | $ | 0.28 |   |
| Diluted                                                    |   | $                          | 0.15   |   |                     | $      | 0.15 |   |   | $ | 0.29 |   |   | $ | 0.28 |   |

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|                           |   | Three Months EndedJune 30, |      |   | Six Months EndedJune 30, |   |
|--------------------------------|--------|----------------------------|-----------|--------|--------------------------|--------|
|                           |   | 2009                       |      |   | 2008                     |   |   | 2009 |   |   | 2008 |   |
| Number of anti-dilutive shares |   |                       | 1,557,185 |   |                     |   | 1,239,435 |   |   |   | 2,439,736 |   |   |   | 1,707,985 |   |

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| Goodwill:                                    |   | In Thousands |   |
|----------------------------------------------|--------|--------------|--------|
| Balance at December 31, 2008                 |   | $            | 10,353 |   |
| Amortization relating to deferred tax assets |   |         | (10    | ) |
| Balance at June 30, 2009                     |   | $            | 10,343 |   |

| Intangible Assets:           |   | In Thousands |   |
|------------------------------|--------|--------------|--------|
| Balance at December 31, 2008 |   | $            | 176    |   |
| Amortization                 |   |         | (32    | ) |
| Balance at June 30, 2009     |   | $            | 144    |   |

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|                                       |   | Balance atJune 30, 2009 |   |   | Level 1 |   |   | Level 2 |   |   | Level 3 |   |
|--------------------------------------------|--------|-------------------------|--------|--------|---------|--------|--------|---------|--------|--------|---------|--------|
|                                       |   | (In thousands)          |   |
| Assets:                                    |   |                    |   |   |    |   |   |    |   |   |    |   |
| Money market funds                         |   | $                       | 18,992 |   |    | $      | 18,992 |    |   |   | -       |   |   |   | - |   |
| Short-term investments                     |   | $                       | 56,553 |   |    |   | -      |    |   | $      | 56,553  |   |   |   | - |   |
| Restricted cash – money market funds |   | $                       | 2,167  |   |    | $      | 2,167  |    |   |   | -       |   |   |   | - |   |
| Restricted long-term investments           |   | $                       | 631    |   |    |   | -      |    |   | $      | 631     |   |   |   | -  |   |

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| ▪ | Revenue, before fuel surcharge, decreased 6.8%, to $144.3 million from $154.8 million; |
|---------|----------------------------------------------------------------------------------------|
|    |                                                                                   |
| ▪ | Net income increased 1.0% to $12.6 million, compared to $12.7 million; and             |
|    |                                                                                   |
| ▪ | Net income per diluted share remained at $0.15 for both periods.                       |

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|                                                       |   | (A)(Fuel surcharge included in revenue)Three-MonthPeriod EndedJune 30, |   |   | (B)(Fuel surcharge excluded from revenue and netted to fuel expense)Three-MonthPeriod EndedJune 30, |   |   | (C)(Fuel surcharge included in revenue)Six-MonthPeriod EndedJune 30, |   |   | (D) (Fuel surcharge excluded from revenue and netted to fuel expense)Six-MonthPeriod EndedJune 30, |   |
|------------------------------------------------------------|--------|------------------------------------------------------------------------|--------|--------|-----------------------------------------------------------------------------------------------------|--------|--------|----------------------------------------------------------------------|--------|--------|--------------------------------------------------------------------------------------------------------------|--------|
|                                                       |   |                                                                   |   |   |                                                                                                |   |   |                                                                 |   |   |                                                                                                         |   |   |   |   |   |   |   |   |   |   |   |   |   |
|                                                       |   | 2009                                                                   |   |   | 2008                                                                                                |   |   | 2009                                                                 |   |   | 2008                                                                                                         |   |   | 2009 |   |   | 2008 |   |   | 2009 |   |   | 2008 |   |
|                                                       |   |                                                                   |   |   |                                                                                                |   |   |                                                                 |   |   |                                                                                                         |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Revenue                                                    |   |                                                                   | 100.0  | %      |                                                                                                |   | 100.0  | %                                                                    |   |   | 100.0                                                                                                        | %      |   |   | 100.0 | % |   |   | 100.0 | % |   |   | 100.0 | % |   |   | 100.0 | % |   |   | 100.0 | % |
|                                                       |   |                                                                   |   |   |                                                                                                |   |   |                                                                 |   |   |                                                                                                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Operating expenses: *                                      |   |                                                                   |   |   |                                                                                                |   |   |                                                                 |   |   |                                                                                                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Salaries, wages and benefits                               |   |                                                                   | 30.9   |   |                                                                                                |   | 26.1   |                                                                 |   |   | 34.7                                                                                                         |   |   |   | 34.7 |   |   |   | 31.6 |   |   |   | 27.2 |   |   |   | 35.4 |   |   |   | 35.1 |   |
| Fuel                                                       |   |                                                                   | 20.7   |   |                                                                                                |   | 35.3   |                                                                 |   |   | 10.9                                                                                                         |   |   |   | 13.9 |   |   |   | 20.1 |   |   |   | 33.0 |   |   |   | 10.5 |   |   |   | 13.5 |   |
| Operations and maintenance                                 |   |                                                                   | 6.6    |   |                                                                                                |   | 5.2    |                                                                 |   |   | 7.4                                                                                                          |   |   |   | 6.9 |   |   |   | 6.7 |   |   |   | 5.2 |   |   |   | 7.5 |   |   |   | 6.7 |   |
| Insurance and claims                                       |   |                                                                   | 3.3    |   |                                                                                                |   | 3.7    |                                                                 |   |   | 3.7                                                                                                          |   |   |   | 5.0 |   |   |   | 3.4 |   |   |   | 3.9 |   |   |   | 3.9 |   |   |   | 5.0 |   |
| Operating taxes and licenses                               |   |                                                                   | 2.1    |   |                                                                                                |   | 1.9    |                                                                 |   |   | 2.4                                                                                                          |   |   |   | 2.5 |   |   |   | 2.3 |   |   |   | 2.0 |   |   |   | 2.5 |   |   |   | 2.5 |   |
| Communications                                             |   |                                                                   | 0.8    |   |                                                                                                |   | 0.7    |                                                                 |   |   | 1.0                                                                                                          |   |   |   | 1.0 |   |   |   | 0.9 |   |   |   | 0.8 |   |   |   | 1.0 |   |   |   | 1.0 |   |
| Depreciation and amortization                              |   |                                                                   | 10.9   |   |                                                                                                |   | 8.3    |                                                                 |   |   | 12.2                                                                                                         |   |   |   | 11.0 |   |   |   | 11.4 |   |   |   | 8.9 |   |   |   | 12.7 |   |   |   | 11.5 |   |
| Lease expense – revenue equipment                    |   |                                                                   | 0.0    |   |                                                                                                |   | 0.0    |                                                                 |   |   | 0.0                                                                                                          |   |   |   | 0.0 |   |   |   | 0.0 |   |   |   | 0.0 |   |   |   | 0.0 |   |   |   | 0.0 |   |
| Purchased transportation                                   |   |                                                                   | 9.4    |   |                                                                                                |   | 7.1    |                                                                 |   |   | 10.6                                                                                                         |   |   |   | 9.4 |   |   |   | 8.4 |   |   |   | 7.2 |   |   |   | 9.4 |   |   |   | 9.3 |   |
| Miscellaneous operating expenses                           |   |                                                                   | 2.4    |   |                                                                                                |   | 1.6    |                                                                 |   |   | 2.7                                                                                                          |   |   |   | 2.2 |   |   |   | 2.3 |   |   |   | 1.5 |   |   |   | 2.6 |   |   |   | 2.1 |   |
| Total operating expenses                                   |   |                                                                   | 87.1   |   |                                                                                                |   | 89.9   |                                                                 |   |   | 85.6                                                                                                         |   |   |   | 86.6 |   |   |   | 87.1 |   |   |   | 89.7 |   |   |   | 85.5 |   |   |   | 86.7 |   |
| Income from operations                                     |   |                                                                   | 12.9   |   |                                                                                                |   | 10.1   |                                                                 |   |   | 14.4                                                                                                         |   |   |   | 13.4 |   |   |   | 12.9 |   |   |   | 10.3 |   |   |   | 14.5 |   |   |   | 13.3 |   |
| Net interest income                                        |   |                                                                   | 0.2    |   |                                                                                                |   | 0.1    |                                                                 |   |   | 0.2                                                                                                          |   |   |   | 0.1 |   |   |   | 0.2 |   |   |   | 0.1 |   |   |   | 0.2 |   |   |   | 0.1 |   |
| Other income                                               |   |                                                                   | 0.0    |   |                                                                                                |   | 0.1    |                                                                 |   |   | 0.0                                                                                                          |   |   |   | 0.2 |   |   |   | 0.0 |   |   |   | 0.1 |   |   |   | 0.0 |   |   |   | 0.1 |   |
| Income before income taxes                                 |   |                                                                   | 13.1   |   |                                                                                                |   | 10.3   |                                                                 |   |   | 14.6                                                                                                         |   |   |   | 13.7 |   |   |   | 13.1 |   |   |   | 10.5 |   |   |   | 14.7 |   |   |   | 13.5 |   |
| Income taxes                                               |   |                                                                   | 5.3    |   |                                                                                                |   | 4.1    |                                                                 |   |   | 5.9                                                                                                          |   |   |   | 5.5 |   |   |   | 5.3 |   |   |   | 4.2 |   |   |   | 6.0 |   |   |   | 5.4 |   |
| Net income                                                 |   |                                                                   | 7.8    | %      |                                                                                                |   | 6.2    | %                                                                    |   |   | 8.7                                                                                                          | %      |   |   | 8.2 | % |   |   | 7.8 | % |   |   | 6.3 | % |   |   | 8.7 | % |   |   | 8.1 | % |
|                                                       |   |                                                                   |   |   |                                                                                                |   |   |                                                                 |   |   |                                                                                                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| *  There are minor rounding differences in the table. |   |

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Item 3.

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Item 4. 

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Item 1. 

Item 1A.

Item 2.

Item 3.

Item 4.

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|             | Votes For  |   | VotesAgainst or Withheld/Abstentions |
|------------------|------------|--------|--------------------------------------|
|             |       |   |                                 |
| Gary J. Knight   | 71,227,027 |   | 2,133,831                            |
| G.D. Madden      | 68,466,621 |   | 4,894,237                            |
| Kathryn L. Munro | 68,948,501 |   | 4,412,357                            |

| Votes For:                 | 65,117,470 |
|----------------------------|------------|
| Votes Against or Withheld: | 97,321     |
| Abstentions:               | 19,836     |
| Broker Non-Votes:          | 8,126,231  |

| Votes For:                 | 62,181,028 |
|----------------------------|------------|
| Votes Against or Withheld: | 2,674,779  |
| Abstentions:               | 378,819    |
| Broker Non-Votes:          | 8,126,232  |

| Votes For:                 | 25,364,866 |
|----------------------------|------------|
| Votes Against or Withheld: | 39,491,549 |
| Abstentions:               | 378,211    |
| Broker Non-Votes:          | 8,126,232  |

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| Votes For:                 | 73,327,920 |
|----------------------------|------------|
| Votes Against or Withheld: | 15,673     |
| Abstentions:               | 17,264     |

Item 5.

Item 6. 

| Exhibit No. |             | Description                                                                                                                                                                                                               |
|-------------|------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|        |             |                                                                                                                                                                                                                      |
| Exhibit 3   |             | Articles of Incorporation and Bylaws                                                                                                                                                                                      |
|        |             |                                                                                                                                                                                                                      |
|        | (3.1)            | Second Amended and Restated Articles of Incorporation of the Company.  (Incorporated by reference to Appendix A to the Company's Definitive Proxy Statement on Schedule 14A filed April 20, 2007.)              |
|        |             |                                                                                                                                                                                                                      |
|        | (3.2)            | Sixth Amended and Restated Bylaws of the Company.  (Incorporated by reference to Exhibit 3 to the Company's Report on Form 8-K dated December 18, 2007 and filed on December 19, 2007.)                         |
|        |             |                                                                                                                                                                                                                      |
| Exhibit 4   |             | Instruments defining the rights of security holders, including indentures                                                                                                                                                 |
|        |             |                                                                                                                                                                                                                      |
|        | (4.1)            | Articles 4, 10, and 11 of the Second Amended and 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 Sixth Amended and 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 and Equity Compensation Plan.  (Incorporated by reference to the Company's Definitive Proxy Statement on Schedule 14A filed April 10, 2009.) |
|        |             |                                                                                                                                                                                                                      |
|        | (4.4)            | Knight Transportation, Inc. Employee Stock Purchase Plan.  (Incorporated by reference to the Company's Definitive Proxy Statement on Schedule 14A filed April 10, 2009.)                                        |
|        |             |                                                                                                                                                                                                                      |
| Exhibit 10  | (10.1)           | Knight Transportation, Inc. Amended and Restated 2003 Stock Option and Equity Compensation Plan.  (Incorporated by reference to the Company's Definitive Proxy Statement on Schedule 14A filed April 10, 2009.) |
|        |             |                                                                                                                                                                                                                      |
|        | (10.2)           | Knight Transportation, Inc. Employee Stock Purchase Plan.  (Incorporated by reference to the Company's Definitive Proxy Statement on Schedule 14A filed April 10, 2009.)                                        |
|        |             |                                                                                                                                                                                                                      |
| 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: August 10, 2009 | By:    | /s/ Kevin P. Knight                                                              |
|                  |   | Kevin P. Knight                                                                  |
|                  |   | Chief Executive Officer, in his capacity as such and on behalf of the registrant |
|                  |   |                                                                             |
|                  |   |                                                                             |
|                  |   |                                                                             |
| Date: August 10, 2009 | By:    | /s/ David A. Jackson                                                             |
|                  |   | David A. Jackson                                                                 |
|                  |   | Chief Financial Officer, in his capacity as such and on behalf of the registrant |