Certification of the Chief Executive Officer under Rule 13a-14(a)
                                                                    EXHIBIT 31.1

I, William W. Sherertz, certify that:

  1.  I have reviewed  this  Quarterly  Report on Form 10-Q of Barrett  Business
      Services, Inc.;

  2.  Based on my knowledge,  this quarterly  report does not contain any untrue
      statement of a material fact or omit to state a material fact necessary to
      make the statements made, in light of the  circumstances  under which such
      statements were made, not misleading with respect to the period covered by
      this quarterly report;

  3.  Based on my knowledge,  the consolidated  financial statements,  and other
      financial information included in this quarterly report, fairly present in
      all material respects the financial  condition,  results of operations and
      cash flows of the Registrant as of, and for, the periods presented in this
      quarterly report;

  4.  The  Registrant's  other  certifying  officer  and I are  responsible  for
      establishing  and  maintaining  disclosure  controls  and  procedures  (as
      defined in Exchange Act Rules  13a-15(e) and 15d-15(e)) for the Registrant
      and have:

           (a) Designed such disclosure controls and procedures, or caused such
           disclosure controls and procedures to be designed under our
           supervision, to ensure that material information relating to the
           Registrant, including its consolidated subsidiaries, is made known to
           us by others within those entities, particularly during the period in
           which this quarterly report is being prepared;

           (b) Evaluated the effectiveness of the Registrant's disclosure
           controls and procedures and presented in this quarterly report our
           conclusions about the effectiveness of the disclosure controls and
           procedures, as of the end of the period covered by this report based
           on such evaluation; and

           (c) Disclosed in this report any change in the Registrant's internal
           control over financial reporting that occurred during the
           Registrant's most recent fiscal quarter that has materially affected,
           or is reasonably likely to materially affect, the Registrant's
           internal control over financial reporting; and

  5.  The Registrant's other certifying  officer and I have disclosed,  based on
      our most recent  evaluation of internal control over financial  reporting,
      to the  Registrant's  auditors and the audit committee of the Registrant's
      board of directors:

           (a) All significant deficiencies and material weaknesses in the
           design or operation of internal control over financial reporting
           which are reasonably likely to adversely affect the Registrant's
           ability to record, process, summarize and report financial
           information; and

           (b) Any fraud, whether or not material, that involves management or
           other employees who have a significant role in the Registrant's
           internal control over financial reporting.


Date:  November 11, 2004                       /s/ William W. Sherertz
                                               ----------------------------
                                               William W. Sherertz
                                               Chief Executive Officer