Form: 10-Q

Quarterly report pursuant to Section 13 or 15(d)

May 15, 2006

Documents

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350

In connection with the Quarterly Report of Barrett Business Services, Inc. (the “Company”) on Form 10-Q for the period ended March 31, 2006, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned certify, pursuant to 18 U.S.C. § 1350, that:

      (1)        The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

      (2)        The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ William W. Sherertz
William W. Sherertz
Chielf Executive Officer
May 12, 2006 		/s/ Michael D. Mulholland
Michael D. Mulholland
Chief Financial Officer
May 12, 2006