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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
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                                  SCHEDULE 13D

                    Information to be Included in Statements
                       Filed Pursuant to Rule 13d-1(a) and
               Amendments Thereto Filed pursuant to Rule 13d-2(a)
                                (Amendment No. 7)
                         ------------------------------

                         Barrett Business Services, Inc.
                                (Name of Issuer)
                         ------------------------------

                          Common Stock, $.01 par value
                         (Title of Class of Securities)
                         ------------------------------


                                   068463 10 8
                                 (CUSIP Number)
                         ------------------------------

                               William W. Sherertz
                         Barrett Business Services, Inc.
                            4724 S.W. Macadam Avenue
                             Portland, Oregon 97239
                            Telephone: (503) 220-0988
            (Name, Address, and Telephone Number of Person Authorized
                     to Receive Notices and Communications)

                                    Copy to:

                                 Mary Ann Frantz
                                 Miller Nash LLP
                        111 S.W. Fifth Avenue, Suite 3400
                             Portland, Oregon 97204
                            Telephone: (503) 224-5858

                                 March 11, 2005
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  that is the subject of this  Schedule  13D, and is filing this
schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box
[ ].

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CUSIP 068463 10 8                                              Page 2 of 6 pages

                                       13D

1.    Names of Reporting Persons

      I.R.S. Identification Nos. of Above Persons (Entities Only)

      William W. Sherertz

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2.    Check the Appropriate Box if a Member of a Group [ ] (a)
      [  ]  (b)

3.    SEC Use Only

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4.    Source of Funds

      PF, BK

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5.    [  ]  Check Box if Disclosure of Legal Proceedings is
              Required Pursuant to Item 2(d) or 2(e)

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6.    Citizenship or Place of Organization

      United States

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Number of Shares Beneficially Owned by Each Reporting Person With:

7.    Sole Voting Power

      1,863,672

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8.    Shared Voting Power

      40,467

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9.    Sole Dispositive Power

      1,863,672

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10.   Shared Dispositive Power

      40,467

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11. Aggregate Amount Beneficially Owned by Each Reporting Person

      1,904,139

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CUSIP 068463 10 8                                              Page 3 of 6 pages

12.   [  ]  Check Box if the Aggregate Amount in Row 11 Excludes
              Certain Shares

13.   Percent of Class Represented by Amount in Row 11

      32.7 percent

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14.   Type of Reporting Person

      IN

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CUSIP 068463 10 8                                              Page 4 of 6 pages

Item 1.  Security and Issuer.

      The title of the class of equity  securities to which this Amendment No. 7
to statement on Schedule 13D (this  "Statement")  relates is common stock,  $.01
par value  ("Common  Stock"),  of Barrett  Business  Services,  Inc., a Maryland
corporation (the "Company").  The address of the Company's  principal  executive
offices is 4724 S.W. Macadam Avenue, Portland, Oregon 97239.

Item 2.  Identity and Background.

      (a)-(c),  (f) This  statement  is  filed  by  William  W.  Sherertz  ("Mr.
Sherertz"), whose business address is 4724 S.W. Macadam Avenue, Portland, Oregon
97239.  Mr.  Sherertz's  present  principal  occupation  is President  and Chief
Executive  Officer of the Company.  The Company is a human  resource  management
company engaged in providing  staffing and professional  employer  services to a
diversified  group of  customers  through a network  of branch  offices in eight
states.  The Company's address is set forth in Item 1. Mr. Sherertz is a citizen
of the United States.

      (d)-(e)  During  the  last  five  years,  Mr.  Sherertz  has not (i)  been
convicted in a criminal  proceeding  (excluding  traffic  violations  or similar
misdemeanors)  or (ii)  been a party  to a civil  proceeding  of a  judicial  or
administrative body of competent jurisdiction and as a result of such proceeding
was or is  subject  to a  judgment,  decree  or  final  order  enjoining  future
violations  of, or prohibiting  or mandating  activities  subject to, federal or
state securities laws or finding any violation with respect to such laws.

Item 3.  Source and Amount of Funds or Other Consideration.

      Since May 10, 2004,  the filing date of Amendment No. 6 to this  Statement
("Amendment No. 6"), Mr. Sherertz has:

            (a) Sold a total of  75,000  shares of  Common  Stock in three  open
      market   transactions   for  a  total  purchase  price  of   approximately
      $1,695,000; and

            (b) Disposed of 8,095 shares of Common  Stock in  satisfaction  of a
      debt to the Company in the approximate amount of $136,280.

      Mr. Sherertz's wife also sold 833 shares of Common Stock in an open market
transaction for a purchase price of approximately $12,703.

      The  source  and  amount of funds or other  consideration  used to acquire
Common  Stock prior to filing of  Amendment  No. 6 were  previously  reported in
Amendment No. 6.

Item 4.  Purpose of Transaction.

      Mr.  Sherertz  acquires or disposes of shares of Common Stock from time to
time for  personal  reasons.  Except in the  ordinary  course of Mr.  Sherertz's
management  of the Company in his  capacity  as  President  and Chief  Executive
Officer, Mr. Sherertz has no present plans or proposals which relate to or would
result in:

            (a) The  acquisition  by any person of additional  securities of the
      Company other than grants to and exercises of employee  stock options held
      by Mr. Sherertz from



CUSIP 068463 10 8                                              Page 5 of 6 pages


      time to time, or the  disposition  of securities of the Company other than
      by  gift  undertaken  by Mr.  Sherertz  for  charitable  or  tax  planning
      purposes;

            (b)  An  extraordinary  corporate  transaction,  such  as a  merger,
      reorganization  or  liquidation,  involving  the  Company  or  any  of its
      subsidiaries;

            (c) A sale or transfer of a material amount of assets of the Company
      or any of its subsidiaries;

            (d) Any change in the present  board of directors or  management  of
      the Company, including any plans or proposals to change the number or term
      of directors or to fill any existing vacancies on the board;

            (e) Any material  change in the present  capitalization  or dividend
      policy of the Company;

            (f) Any other material change in the Company's business or corporate
      structure;

            (g)  Changes  in  the  Company's  charter,   bylaws  or  instruments
      corresponding thereto or other actions which may impede the acquisition of
      control of the Company by any person;

            (h) Causing a class of securities of the Company to be delisted from
      a national  securities  exchange or to cease to be authorized to be quoted
      in an inter-dealer  quotation system of a registered  national  securities
      association;

            (i) A class of equity  securities of the Company  becoming  eligible
      for  termination  of  registration  pursuant  to Section  12(g)(4)  of the
      Securities Exchange Act of 1934; or

            (j) Any action similar to any of those enumerated above.

Item 5.  Interest in Securities of the Issuer.

      (a)-(b) Mr. Sherertz beneficially owns 1,904,139 shares of Common Stock or
32.7 percent of the  outstanding  Common Stock.  Mr.  Sherertz has sole power to
vote and sole power to dispose of 1,863,672 shares, which includes 85,134 shares
subject to options that are  presently  exercisable  or will become  exercisable
within 60 days of the date of this Statement.  In addition,  Mr. Sherertz shares
voting and  dispositive  powers as to 9,167  shares  held by his wife and 31,300
shares held by Mr. Sherertz for his minor children.

      (c) During the past 60 days,  Mr.  Sherertz sold shares of Common Stock as
follows:
                                                            Total Sale
           Date         No. of Shares   Price Per Share      Proceeds

          3/10/05          52,500          $22.60          $1,186,500
          3/11/05          10,000           22.60             226,000
          3/14/05          12,500           22.60             282,500
                           ------                            --------
           Total           75,000                          $1,695,000



CUSIP 068463 10 8                                              Page 6 of 6 pages

      (d)-(e)     Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to
Securities of the Issuer.

      Mr. Sherertz entered into a letter  agreement,  dated August 17, 1992 (the
"Agreement"),  with Nancy B.  Sherertz  pursuant  to which they agreed to divide
their  holdings  of  Company  capital  stock  equally  upon  the  closing  of an
underwriting  agreement for an initial public offering of Company capital stock.
The Agreement was entered into by Ms. Sherertz for personal reasons based on her
then  marital   relationship  with  Mr.  Sherertz  and  also  to  recognize  his
contribution  to the  Company's  growth and his  efforts to  establish  a public
market for the Common Stock.  The  Agreement  was fully  performed in connection
with  the  Company's  initial  public  offering  in June  1993.  Except  for the
Agreement and award agreements for employee stock options in  substantially  the
form referred to in Item 7, there are no contracts, arrangements, understandings
or relationships  (legal or otherwise) between Mr. Sherertz and any other person
with  respect to any  securities  of the Company,  including  but not limited to
transfer or voting of any of the securities, finders' fees, joint ventures, loan
or option  arrangements,  puts or calls,  guarantees  of  profits,  division  of
profits or loss, or the giving or withholding of proxies.

Item 7.  Material to be Filed as Exhibits.

            (a)  Letter  agreement  between  Nancy B.  Sherertz  and  William W.
      Sherertz dated August 17, 1992. (Incorporated by reference to Exhibit 10.6
      to the  Company's  registration  statement  on  Form  S-1  (No.  33-61804)
      effective June 11, 1993.)

            (b) Form of Nonqualified  Stock Option Agreement under the Company's
      2003 Stock Incentive Plan.  (Incorporated by reference to Exhibit 10.12 to
      the Company's  annual report on Form 10-K for the year ended  December 31,
      2003.)*

-----------

*     Individual agreements representing grants of employee stock options to Mr.
Sherertz are  substantially  identical to Exhibit (b) except for exercise  price
and dates of vesting and expiration.

                                    SIGNATURE

      After  reasonable  inquiry and to the best of my knowledge  and belief,  I
certify that the information  set forth in this Statement is true,  complete and
correct.


Dated:  March 17, 2005                    /s/ William W. Sherertz
                                          --------------------------------------
                                          William W. Sherertz

Attention:  Intentional  misstatements  or omissions of fact constitute  Federal
criminal violations. (See 18 U.S.C. 1001.)