EXHIBIT 31.1

I, Jeffrey A. Patterson, certify that:

     1.  I have  reviewed  this annual report on Form 10-K of Prime Group Realty
         Trust;

     2.  Based on my  knowledge,  this annual 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 annual report;

     3.  Based on my knowledge,  the financial  statements,  and other financial
         information  included  in this  annual  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 annual 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))  and internal
         controls  over  financial  reporting  (as defined in Exchange Act Rules
         13a-15(f) and 15d-15(f) for the registrant and we 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  annual  report  is being
                  prepared;

b)                designed such internal controls over financial  reporting,  or
                  caused such internal  controls over financial  reporting to be
                  designed  under  our   supervision,   to  provide   reasonable
                  assurance regarding the reliability of financial reporting and
                  the preparation of financial  statements for external purposes
                  in accordance with generally accepted accounting principles;

c)                evaluated the  effectiveness  of the  registrant's  disclosure
                  controls and  procedures  and  presented in this annual report
                  our  conclusions  about the  effectiveness  of the  disclosure
                  controls and  procedures,  as of the end of the period covered
                  by this annual report based on such evaluation; and

d)                disclosed in this annual report any change in the registrant's
                  internal control over financial reporting that occurred during
                  the registrant's  most recent fiscal quarter (the registrant's
                  fourth  fiscal  quarter in the case of an annual  report) 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
         registrant's  board of directors (or persons  performing the equivalent
         functions):

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:  March 1, 2005

         /s/ Jeffrey A. Patterson
         Jeffrey A. Patterson
         President and Chief Executive Officer


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