Exhibit 5

                                 MILLER NASH LLP
                                ATTORNEYS AT LAW
                            3500 U. S. BANCORP TOWER
                              111 S.W. FIFTH AVENUE
                           PORTLAND, OREGON 97204-3699
                            TELEPHONE (503) 224-5858
                            FACSIMILE (503) 224-0155


                                November 22, 2000


Barrett Business Services, Inc.
4724 S.W. Macadam Avenue
Portland, Oregon  97201

             Subject:   Registration Statement on Form S-8 Relating to 1993
                        Stock Incentive Plan

Ladies and Gentlemen:

            Reference  is  made  to  the  Registration  Statement  on  Form  S-8
("Registration  Statement") to be filed by Barrett  Business  Services,  Inc., a
Maryland   corporation  (the  "Company"),   with  the  Securities  and  Exchange
Commission for the purpose of  registering  under the Securities Act of 1933, as
amended (the  "Securities  Act"), an additional  250,000 shares (the "Registered
Shares") of the Company's Common Stock, $.01 par value ("Common  Stock"),  to be
issued under the  Company's  1993 Stock  Incentive  Plan,  as amended  ("Amended
Plan"), together with options and other rights relating thereto.

            We  have  examined  originals  or  copies,  certified  or  otherwise
identified to our  satisfaction,  of such  corporate  records,  certificates  of
public officials, and other documents as we have deemed necessary or relevant as
a basis for the opinion set forth herein.

            Based on the foregoing, it is our opinion that:

            1. The  Amended  Plan has been  duly  adopted  and  approved  by all
               necessary  corporate  action and when  options or other  rights
               relating to the 250,000 shares of Common Stock referred to above
               have been granted in accordance with the Amended Plan, such
               options or rights will have been legally issued.

            2. The 250,000  shares of Common  Stock  referred to above have been
               duly authorized and reserved for issuance.

            3. When such shares are issued and sold by the Company upon exercise
               of options or issued  pursuant to other  rights duly  granted
               under the Amended Plan while the Registration Statement is
               effective,  and payment for such shares to the extent and in the
               manner  required by the Amended Plan is received by the Company,
               such shares will be legally issued, fully paid and nonassessable.

            We consent to the use of this opinion in the Registration  Statement
and in any amendments  thereof.  In giving this consent, we do not thereby admit
that we are in the category of persons whose consent is required under Section 7
of the Securities Act.

                                          Very truly yours,



                                          MILLER NASH LLP