For  Immediate Release
 Phoenix,  Arizona - April 20, 2005
 Contacts:
 Kevin  P. Knight, Chairman & CEO
 David  Jackson, CFO
 (602)  269-2000

 Knight  Transportation Posts Record Revenue and Net Income for the First Quarter of  2005 
 
Knight  Transportation, Inc. (NYSE: KNX) announced today its financial results for the  quarter ended March 31, 2005.

 Total  revenue for the quarter increased 30% to $122.2 million, compared to the first  quarter of 2004. Revenue, before fuel surcharge, increased 23% to $111.1 million  from $90.2 million for the same quarter of 2004. Net income increased 37% to  $12.8 million from $9.3 million for the same period of 2004. Net income per  diluted share increased to $0.22 from $0.16 for same quarter 2004.

 Chairman  and Chief Executive Officer Kevin P. Knight commented on the  quarter:

 “We are  encouraged by another quarter of record revenue and earnings as we continued to  execute our operating model focused on leading growth and profitability. We were  pleased with revenue growth of 23%, before fuel surcharge, and 30% including  fuel surcharge. In addition to our industry-leading growth and despite  significant fuel, driver pay and other cost pressures facing our industry, we  improved our margins. Our operating ratio (operating expenses, net of fuel  surcharge, as a percentage of revenue, before fuel surcharge) improved by 190  basis points to 81.0%, which is our best first quarter operating ratio since the  first quarter of 1994. Our net income was 11.5% of revenue, before fuel  surcharge, which is the best first quarter in our history. We achieved these  results through a combination of expanding our fleet and continued pricing  improvement, while not taking our eye off of controlling costs.

 Our  average tractors operating in the first quarter were up over 16% from the same  period of 2004. Our average freight revenue per loaded and total mile, before  fuel surcharges, increased 9.8% and 9.1%, respectively, without sacrificing  length of haul which was up 6.0%. Even though our miles per tractor were down  3.2%, we were able to produce an increase of 5.8% in our revenue per tractor,  excluding fuel surcharge. Our footprint expansion continues with the recently  announced opening of our 18   th   dry van  operations center in Chicago, the first of our scheduled new operations centers  in 2005.

 Rapidly  escalating fuel prices are a significant challenge for our industry, and our  sales and operations associates are working diligently with our customers to  mitigate the negative impact of fuel prices. For the quarter, we increased fuel  surcharge billings by 173% compared with the same quarter of last year. These  efforts helped us limit the negative impact of fuel prices.

 During  the quarter we continued to make significant investments in revenue equipment to  support our growth. We added 87 new tractors while upgrading an additional 86  existing tractors. We anticipate growing our fleet by an additional 300 to 350  tractors over the remainder of 2005. We were able to reduce our trailer fleet by  47, while upgrading 102 trailers. For the quarter, we invested $13.3 million in  net capital expenditures. At March 31, 2005, our strong balance sheet reflected  $38.7 million in cash, no debt, and $303.9 million in shareholders’  equity.”

 The  Company will hold a conference call on April 21, 4:00 ET, to further discuss its  results of operations for the quarter ended March 31, 2005. The dial in number  for this conference call is (800) 475-3716.
 
 Excludes  fuel surcharge.
**
 Operating  ratio as reported in this press release is based upon total operating  expenses, net of fuel surcharge, as a percentage of revenue, before fuel  surcharge. Revenue from fuel surcharge is available on the accompanying  statements of income. We measure our revenue, before fuel surcharge, and  our operating expenses, net of fuel surcharge, because we believe that  eliminating this sometimes volatile source of revenue affords a more  consistent basis for comparing our results of operations from period to  period.

 Knight  Transportation, Inc. is a short to medium haul, truckload carrier headquartered  in Phoenix, Arizona. The Company serves most of the United States through its  regional operations in Phoenix, AZ; Salt Lake City, UT; Portland, OR; Las Vegas,  NV; Denver, CO; Kansas City, KS; Indianapolis, IN; Katy, TX; Gulfport, MS;  Charlotte, NC; Memphis, TN, Atlanta, GA; Carlisle, PA; Lakeland, FL and Chicago,  IL. The Company transports general commodities, including consumer goods,  packaged foodstuffs, paper products, beverage containers, imported and exported  commodities and refrigerated goods.

 This  press release may contain statements that might be considered as forward-looking  statements or predictions of future operations. Such statements are based on  management's belief or interpretation of information currently available. These  statements and assumptions involve certain risks and uncertainties. Actual  events may differ from these expectations as specified from time to time in  filings with the Securities and Exchange Commission.

 Contact:  Kevin P. Knight, Chairman & CEO or Dave Jackson, CFO, at (602)  269-2000