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                                                                  Exhibit 5.1








                                                     February 20, 1998


Brandywine Realty Trust
16 Campus Boulevard
Newtown Square, PA  19073

                  Re:  Form S-3 Registration Statement
                       -------------------------------


Gentlemen:

         We have acted as counsel to Brandywine Realty Trust, a Maryland real
estate investment trust (the "Company"), in connection with the preparation of a
registration statement (the "Registration Statement") of the Company on Form S-3
under the Securities Act of 1933, as amended (the "Act"), and the filing of the
Registration Statement with the Securities and Exchange Commission (the
"Commission"). The Registration Statement relates to the offer and sale from
time to time of up to 389,976 common shares of beneficial interest, par value
$.01 per share ("Common Shares"), of the Company by holders identified under the
caption "Selling Shareholders" in the Prospectus included in the Registration
Statement.

         In connection with this opinion, we have examined the originals or
copies, certified or otherwise identified to our satisfaction, of the
Registration Statement, the Declaration of Trust and the Bylaws of the Company,
as amended to date, resolutions of the Company's Board of Trustees and such
other documents and trust records relating to the Company as we have deemed
appropriate. Insofar as this opinion relates to matters of Maryland law, we have
relied exclusively upon the opinion of Ballard Spahr Andrews & Ingersoll
addressed to the Company, dated February 20, 1998.

         Based upon the foregoing, we are of the opinion that the Common Shares
subject to issuance upon redemption of Units (as defined in the Registration
Statement) will, upon such issuance in accordance with the terms of such Units,
be validly issued, fully paid and nonassessable.

         We assume no obligation to supplement this opinion if any applicable
law changes after the date hereof or if we become aware of any fact that might
change the opinion expressed herein after the date hereof.

         We hereby consent to the reference to our firm under the section "Legal
Matters" in the Prospectus included in the Registration Statement and to the
filing of this opinion as an exhibit to the Registration Statement. In giving
this consent, we do not admit that we are within the category of persons whose
consent is required by Section 7 of the 1933 Act.

                                                     Very truly yours,




                                                     PEPPER HAMILTON LLP

