PS Business Parks
                                  701 Western Avenue, Glendale, California 91201

                                  July 15, 2009

   Via EDGAR and facsimile (703) 813-6984

   Sonia Barros
   Special Counsel
   Division of Corporation Finance
   Securities and Exchange Commission
   100 F Street, NE
   Washington, D.C. 20549

         Re:    Request  for   Acceleration  of  Effectiveness  of  Registration
                Statement  on  Form  S-3  (Registration  No.  333-160104)  of PS
                Business Parks, Inc.

   Dear Ms. Barros:

         PS Business Parks, Inc. (the "Registrant")  hereby requests pursuant to
   Rule 461 of the rules and regulations promulgated under the Securities Act of
   1933, as amended,  that the  effectiveness of its  Registration  Statement on
   Form S-3 (Registration  Statement No.  333-160104) be accelerated so that the
   Registration  Statement will become effective on Friday,  July 17, 2009, at 1
   p.m., Eastern time, or as soon thereafter as practicable.

         In connection with this request, the Registrant acknowledges that:

         o  should the  Commission  or the staff,  acting  pursuant to delegated
            authority,  declare the filing effective,  it does not foreclose the
            Commission from taking any action with respect to the filing;

         o  the  action of the  Commission  or the  staff,  acting  pursuant  to
            delegated  authority,  in declaring the filing  effective,  does not
            relieve the Registrant from its full responsibility for the adequacy
            and accuracy of the disclosure in the filing; and

         o  the Registrant may not assert staff comments and the  declaration of
            effectiveness  as a  defense  in  any  proceeding  initiated  by the
            Commission  or any person under the federal  securities  laws of the
            United States.

         Please contact me with any questions at (818) 244-8080, extension 1319,
   or fax number (818) 548-9288. I would also appreciate  notification when this
   request for acceleration has been granted.

                                          Very truly yours,

                                          PS BUSINESS PARKS, INC.

                                          By:   /s/ Stephanie G. Heim

                                              Stephanie G. Heim
                                              Vice President, Corporate Counsel
                                              and Assistant Secretary

cc:   Erin E. Martin, Esq., Attorney-Advisor
      Division of Corporation Finance