CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


In connection with the Quarterly Report of Barrett Business Services, Inc. (the
"Company") on Form 10-Q for the period ended June 30, 2002 as filed with the
Securities and Exchange Commission on the date hereof (the "Report"), I, Michael
D. Mulholland, Chief Financial Officer of the Company, certify, pursuant to 18
U.S.C. ss. 1350, as adopted pursuant to ss. 906 of the Sarbanes-Oxley Act of
2002, 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 result of operations of the Company.



/s/ Michael D. Mulholland
- ------------------------------------
Michael D. Mulholland
Chief Financial Officer
August 12, 2002