News Release

PS Business Parks, Inc.
701 Western Avenue
Glendale, CA  91201-2349
www.psbusinessparks.com


                                           For Release: Immediately
                                           Date:        September  21, 2005
                                           Contact:     Mr. Edward A. Stokx
                                                        (818) 244-8080, Ext. 649

PS  BUSINESS  PARKS,  INC.  TO RELEASE  THIRD  QUARTER  2005  EARNINGS  AND HOST
QUARTERLY CONFERENce Call

GLENDALE,  California - PS Business Parks, Inc. (AMEX: PSB) announced today that
it  intends  to  release  its third  quarter  2005  earnings  after the close of
business on Monday, October 31, 2005.

A conference  call is scheduled  for  Tuesday,  November 1, 2005,  at 10:00 a.m.
(PST)  to  discuss  the  third  quarter   results.   The  toll  free  number  is
1-800-399-4409;  the  conference ID is 9553616.  The call will also be available
via a live webcast on the Company's  website.  A replay of the  conference  call
will be available  through November 8, 2005 at  1-800-642-1687.  A replay of the
conference call webcast will also be available on the Company's website.


Company Information
- -------------------

PSB is a self-advised and self-managed  equity real estate investment trust that
acquires,  develops,  owns and operates commercial  properties,  primarily flex,
multi-tenant  office and industrial  space.  The Company defines "flex" space as
buildings that are configured  with a combination of office and warehouse  space
and can be  designed  to fit a  number  of  uses  (including  office,  assembly,
showroom,  laboratory,  light manufacturing and warehouse space). As of June 30,
2005, PSB wholly owned  approximately  17.9 million net rentable  square feet of
commercial  space with  approximately  3,300 customers  located in eight states,
concentrated  primarily in California (5.1 million sq. ft.),  Texas (2.9 million
sq. ft.), Florida (3.3 million sq. ft.), Oregon (1.9 million sq. ft.),  Virginia
(2.8 million sq. ft.) and Maryland (1.2 million sq. ft.).

Additional  information  about PS  Business  Parks,  Inc.  is  available  on the
Internet. The Company's website is www.psbusinessparks.com.


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