EXHIBIT 32.1

Certification Pursuant to 18 U.S.C. Section 1350 as Adopted
Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

Solely for the purpose of Section 906 of the Sarbanes-Oxley Act of 2002, and solely to the extent this certification is applicable to the Quarterly Report on Form 10-Q for the quarter ended October 29, 2005 of Stewart & Stevenson Services, Inc. (the “Report”), the undersigned hereby certify that the Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Stewart & Stevenson Services, Inc.

	/s/ Max L. Lukens
	Name:	Max L. Lukens
	Title:	President and Chief Executive Officer
	Date:	December 6, 2005


	/s/ John B. Simmons
	Name:	John B. Simmons
	Title:	Senior Vice President and Chief Financial Officer
	Date:	December 6, 2005