EXHIBIT 5.1




                               September 13, 2004



Brandywine Realty Trust
401 Plymouth Road
Suite 500
Plymouth Meeting, PA 19462


Ladies and Gentlemen:

         We have served as counsel to Brandywine Realty Trust, a Maryland real
estate investment trust (the "Company"), in connection with the offer and sale
of up to 8,912,500 common shares of beneficial interest, par value $0.01 per
share (the "Common Shares") of the Company (the "Shares," of which 7,750,000
Common Shares are the "Firm Shares" and up to an additional 1,162,500 Common
Shares are the "Additional Shares," which may be issued and sold pursuant to an
underwriter's over-allotment option), pursuant to a Registration Statement on
Form S-3 (Registration No. 333-117078) (the "Registration Statement"), filed
with the Securities and Exchange Commission (the "Commission") under the
Securities Act of 1933, as amended (the "Act"). The Shares will be issued
pursuant to an underwriting agreement, dated as of September 13, 2004 (the
"Underwriting Agreement"), by and among Citigroup Global Markets Inc., the
Company and Brandywine Operating Partnership, L.P. (the "Operating
Partnership"). Capitalized terms used but not defined herein shall have the
meanings given to them in the Registration Statement.

         In connection with our representation of the Company, and as a basis
for the opinion hereinafter set forth, we have examined originals, or copies
certified or otherwise identified to our satisfaction, of the following
documents (hereinafter collectively referred to as the "Documents"):

         1. The Registration Statement and the related form of prospectus (the
"Prospectus") relating to the Shares included therein in the form in which it
was transmitted to the Commission under the Act;

         2. The Declaration of Trust of the Company, as amended and supplemented
through the date hereof (the "Declaration of Trust"), certified as of a recent
date by the State Department of Assessments and Taxation of Maryland (the
"SDAT");

         3. The Bylaws of the Company (the "Bylaws"), certified as of a recent
date by an officer of the Company;

         4. A certificate of the SDAT as to the good standing of the Company,
dated as of a recent date;





         5. Resolutions (the "Resolutions") adopted by the Board of Trustees of
the Company, or a duly authorized committee thereof, relating to the issuance of
the Shares, certified as of a recent date by an officer of the Company;

         6. The Underwriting Agreement, certified as of a recent date by an
officer of the Company; and

         7. Such other documents and matters as we have deemed necessary or
appropriate to express the opinion set forth below, subject to the assumptions,
limitations and qualifications stated herein.

         In expressing the opinion set forth below, we have assumed the
following:

         1. Each individual executing any of the Documents, whether on behalf of
such individual or another person, is legally competent to do so.

         2. Each individual executing any of the Documents on behalf of a party
(other than the Company and the Operating Partnership) is duly authorized to do
so.

         3. Each of the parties (other than the Company and the Operating
Partnership) executing any of the Documents has duly and validly executed and
delivered each of the Documents to which such party is a signatory, and the
obligations of such party set forth therein are legal, valid and binding and are
enforceable in accordance with all stated terms.

         4. All Documents submitted to us as originals are authentic. The form
and content of all Documents submitted to us as unexecuted drafts do not differ
in any respect relevant to this opinion from the form and content of such
Documents as executed and delivered. All Documents submitted to us as certified
or photostatic copies conform to the original documents. All signatures on all
Documents are genuine. All public records reviewed or relied upon by us or on
our behalf are true and complete. All statements and information contained in
the Documents are true and complete. There has been no oral or written
modification of or amendment to any of the Documents, and there has been no
waiver of any provision of any of the Documents, by action or omission of the
parties or otherwise.

         5. The Shares will not be issued or transferred in violation of any
restriction contained in the Declaration of Trust.

         Based upon the foregoing, and subject to the assumptions, limitations
and qualifications stated herein, it is our opinion that:

         1. The Company is a real estate investment trust duly formed and
existing under and by virtue of the laws of the State of Maryland and is in good
standing with the SDAT.

         2. The Shares are duly authorized for issuance and, when and if issued
and delivered against payment therefor and otherwise in accordance with the
Declaration of Trust, the Bylaws, the Resolutions and the Underwriting
Agreement, will be validly issued, fully paid and nonassessable.





         The foregoing opinion is limited to the substantive laws of the State
of Maryland and we do not express any opinion herein concerning any other law.
We express no opinion as to compliance with any federal or state securities
laws, including the securities laws of the State of Maryland, or as to federal
or state laws regarding fraudulent transfers. 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.

         This opinion is being furnished to you for your submission to the
Commission as an exhibit to the reports filed on Form 8-K (the "8-K"), to be
filed by the Company and by the Operating Partnership with the Commission on or
about the date hereof. We hereby consent to the filing of this opinion as an
exhibit to the 8-K and to the use of the name of our firm therein and under the
section "Legal Matters" in the Prospectus included in 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 Act.

                                                    Very truly yours,

                                                    /s/ Pepper Hamilton LLP
                                                    -----------------------

                                                    Pepper Hamilton LLP