Exhibit 24
POWER OF ATTORNEY

Know all by these presents, that the undersigned hereby constitutes
and appoints each of Michael D. Mulholland and James D. Miller, signing singly,
the undersigned's true and lawful attorney-in-fact to:

1. Execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of Barrett Business
Services, Inc. (the "Company"), Forms 3, 4, and 5 in accordance with Section
16(a) of the Securities Exchange Act of 1934 and the rules thereunder, and any
other forms or reports the undersigned may be required to file in connection
with the undersigned's ownership, acquisition, or disposition of securities of
the Company; and

2. Do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and execute any such
Form 3, 4, or 5, or other form or report, and timely file such form or report
with the United States Securities and Exchange Commission and any stock exchange
or similar authority as appropriate.

The undersigned hereby grants to each such attorney-in-fact full
power and authority to do and perform any and every act and thing necessary or
proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned could do if
personally present, hereby ratifying and confirming all that such
attorney-in-fact shall lawfully do or cause to be done by virtue of this power
of attorney and the rights and powers herein granted. The undersigned
acknowledges that the foregoing attorneys-in-fact, in serving in such capacity
at the request of the undersigned, are not assuming, and the Company is not
assuming, any of the undersigned's responsibilities to comply with Section 16 of
the Securities Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect until
the undersigned is no longer required to file Forms 3, 4, and 5 with respect to
the undersigned's holdings of and transactions in securities issued by the
Company, unless earlier revoked by the undersigned in a signed writing delivered
to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of this 15th day of December, 2004.


/s/ Jon L. Justesen
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Jon L. Justesen