QuickLinks -- Click here to rapidly navigate through this document

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) April 22, 2003

RUSH ENTERPRISES, INC.
(Exact name of registrant as specified in its charter)

Texas (State or other jurisdiction of incorporation)		0-20797 (Commission File Number)		74-1733016 (IRS Employer Identification No.)
555 IH-35 South, Suite 500, New Braunfels, Texas (Address of principal executive offices)				78130 (Zip Code)

Registrant's telephone number, including area code: (830) 626-5200

(Former name or former address, if changed since last report.)

---

Item 7. Financial Statements, Pro Forma Financial Information and Exhibits.

Item 9. Regulation FD Disclosure.

        On April 22, 2003, Rush Enterprises, Inc. issued a press release announcing its financial results for the first quarter ended March 31, 2003. A copy of the press release is attached as Exhibit 99.1.

Item 12. Results of Operation and Financial Condition.

        On April 22, 2003, Rush Enterprises, Inc. issued a press release announcing its financial results for the first quarter ended March 31, 2003. A copy of the press release is attached as Exhibit 99.1.

        In accordance with General Instruction B.2 and B.6 of Form 8-K, the information in this report shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933 or the Securities Exchange Act of 1934, except as shall be expressly set forth by specific reference in such a filing.

2

---

SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

		RUSH ENTERPRISES, INC.
		By:	/s/  MARTIN A. NAEGELIN, JR.       Martin A. Naegelin, Jr. Senior Vice President and Chief Financial Officer

Dated April 22, 2003

3

---

QuickLinks

SIGNATURES

QuickLinks -- Click here to rapidly navigate through this document

EXHIBIT 99.1

CONTACT:

Martin A. Naegelin, Jr. (830) 626-5230

RUSH ENTERPRISES, INC. REPORTS FIRST QUARTER RESULTS

---

SAN ANTONIO, Tex., April 22, 2003—Rush Enterprises, Inc. (NASDAQ: RUSHA & RUSHB), whose continuing operations includes the largest network of Peterbilt heavy-duty truck dealerships in North America and a John Deere construction equipment dealership in Texas, today announced results for the quarter ended March 31, 2003.

        In the first quarter, the Company's gross revenues totaled $159.6 million, a 1.8 percent decrease from gross revenues of $162.6 million reported for the first quarter ended March 31, 2002. Income from continuing operations was $873,000 or $0.06 per diluted share during the first quarter of 2003 compared to $1.1 million or $.08 per diluted share in the first quarter of 2002. Net income for the quarter was $326,000, or $0.02 per diluted share, compared with net income of $434,000, or $0.03 per share reported in the quarter ended March 31, 2002. The Company recorded a net loss from discontinued operations of $547,000 in the first quarter of 2003. This loss consists primarily of operating costs incurred in the liquidation and closing of the Company's retail center in Hockley, Texas.

        The Company's heavy-duty truck segment recorded revenues of $156.3 million in the first quarter of 2003, compared to $152.0 million in the first quarter of 2002. The Company delivered 795 and 519 new and used trucks, respectively, during the first quarter of 2003 compared to 975 and 482 new and used trucks, respectively, for the same period in 2002. Parts, service and body shop sales increased 8.4 percent from $47.3 million in the first quarter of 2002 to $51.2 million in the first quarter of 2003.

        The Company's construction equipment segment recorded revenues of $8.6 million in the first quarter of 2003 compared to $8.8 million in the first quarter of 2002. New and used construction equipment unit sales revenue decreased $180,000 or 3.1 percent from the first quarter of 2002 to the first quarter of 2003. Parts and service sales increased $200,000, or 8.0 percent, from $2.5 million in the first quarter of 2002 to $2.7 million in the first quarter of 2003. Lease and rental sales decreased $179,000, or 44.9 percent from the first quarter of 2002 to the first quarter of 2003.

        In announcing the results, W. Marvin Rush, Chairman and Chief Executive Officer of Rush Enterprises, said, "We are very pleased to announce our first quarter results. As expected, new truck deliveries decreased during the first quarter due to the new truck pre-buy experienced in the third and fourth quarters of 2002. However, the industry expects new truck deliveries to increase in the last half of 2003 and for the truck market to be strong in 2004 through 2006." Mr. Rush added, "I am pleased with the progress of our newly acquired stores in Florida and Alabama and believe that our Company is well positioned to take advantage of the expected growth over the next three years."

        Rush Enterprises operates the largest network of Peterbilt heavy-duty truck dealerships in North America and a John Deere construction equipment dealership in Texas. Its current operations include a network of dealerships located in Texas, California, Oklahoma, Louisiana, Colorado, Arizona, New Mexico, Alabama and Florida. These dealerships provide an integrated, one-stop source for the retail sale of new and used heavy-duty trucks and construction equipment; aftermarket parts, service and body shop facilities; and a wide array of financial services, including the financing of truck and equipment sales, insurance products and leasing and rentals. The Company is in the process of discontinuing the operations of its retail farm and ranch superstore that serves the greater San Antonio, Texas area.

        Certain statements contained herein, including those concerning industry conditions, are ``forward-looking" statements (as such term is defined in the Private Securities Litigation Reform Act of 1995). Because such statements include risks and uncertainties, actual results may differ materially from those

---

expressed or implied by such forward-looking statements. Factors that could cause actual results to differ materially from those expressed or implied by such forward-looking statements include, but are not limited to, competitive factors, general economic conditions, cyclicality, economic conditions in the new and used truck and construction equipment markets, customer relations, relationships with vendors, the interest rate environment, governmental regulation and supervision, seasonality, distribution networks, product introductions and acceptance, technological change, changes in industry practices, onetime events and other factors described herein and in filings made by the company with the Securities and Exchange Commission.

---

RUSH ENTERPRISES, INC., AND SUBSIDIARIES
CONSOLIDATED BALANCE SHEETS
MARCH 31, 2003 AND DECEMBER 31, 2002

(In Thousands, Except Shares and Per Share Amounts)

					March 31, 2003			December 31, 2002
ASSETS
CURRENT ASSETS:
	Cash and cash equivalents				$	16,181		$	24,763
	Accounts receivable, net					22,972			24,935
	Inventories					109,945			115,333
	Assets held for sale					10,229			16,962
	Prepaid expenses and other					1,542			1,764
Deferred income taxes						4,375			4,375
			Total current assets			165,244			188,132
PROPERTY AND EQUIPMENT, net						117,610			117,859
OTHER ASSETS, net						42,005			38,519
			Total assets		$	324,859		$	344,510
LIABILITIES AND SHAREHOLDERS' EQUITY
CURRENT LIABILITIES:
	Floor plan notes payable				$	83,238		$	89,288
	Current maturities of long-term debt					24,353			24,958
	Advances outstanding under lines of credit					19,129			22,395
	Trade accounts payable					11,692			15,082
	Accrued expenses					23,033			28,414
			Total current liabilities			161,445			180,137
LONG-TERM DEBT, net of current maturities						68,673			69,958
DEFERRED INCOME TAXES, net						14,720			14,720
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS' EQUITY:
	Preferred stock, par value $.01 per share; 1,000 shares authorized; 0 shares outstanding in 2001 and 2002					—			—
	Common stock, par value $.01 per share; 50,000,000 shares authorized; 14,004,088 shares outstanding in 2001 and 2002					140			140
	Additional paid-in capital					39,155			39,155
	Retained earnings					40,726			40,400
			Total shareholders' equity			80,021			79,695
			Total liabilities and shareholders' equity		$	324,859		$	344,510

---

RUSH ENTERPRISES, INC., AND SUBSIDIARIES
CONSOLIDATED STATEMENTS OF INCOME
(In Thousands, Except Per Share Amounts)
(Unaudited)

					Three Months Ended March 31,
					2003			2002
REVENUES:
	New and used truck sales				$	91,218		$	98,219
	Parts and service					54,711			50,811
	Construction equipment sales					5,657			5,837
	Lease and rental					6,124			6,284
	Finance and insurance					1,368			998
	Other					538			410
			Total revenues			159,616			162,559
COST OF PRODUCTS SOLD						125,442			130,429
GROSS PROFIT						34,174			32,130
SELLING, GENERAL AND ADMINISTRATIVE						29,089			26,424
DEPRECIATION AND AMORTIZATION						2,190			2,145
OPERATING INCOME						2,895			3,561
INTEREST EXPENSE, NET						1,548			1,646
GAIN (LOSS) ON SALE OF ASSETS						108			(2	)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES						1,455			1,913
PROVISION FOR INCOME TAXES						582			765
INCOME FROM CONTINUING OPERATIONS						873			1,148
(LOSS) FROM DISCONTINUED OPERATIONS, NET						(547	)		(714	)
NET INCOME					$	326		$	434
EARNINGS (LOSS) PER COMMON SHARE — BASIC
	Income from continuing operations				$	.06		$	.08
	Net income (loss)				$	.02		$	.03
EARNINGS (LOSS) PER COMMON SHARE — DILUTED
	Income from continuing operations				$	.06		$	.08
	Net income (loss)				$	.02		$	.03
Weighted average shares outstanding:
		Basic				14,004			14,004
		Diluted				14,309			14,310

---

QuickLinks

RUSH ENTERPRISES, INC. REPORTS FIRST QUARTER RESULTS
RUSH ENTERPRISES, INC., AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS MARCH 31, 2003 AND DECEMBER 31, 2002 (In Thousands, Except Shares and Per Share Amounts)
RUSH ENTERPRISES, INC., AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF INCOME (In Thousands, Except Per Share Amounts) (Unaudited)