Biomed Realty Trust S-3ASR Automatic shelf registration

Exhibit 8.1

September 4, 2009

BioMed Realty Trust, Inc.
17190 Bernardo Center Drive
San Diego, California 92128

600 West Broadway, Suite 1800
San Diego, California 92101-3375
Tel: +1.619.236.1234 Fax: +1.619.696.7419
www.lw.com

FIRM / AFFILIATE OFFICES
Abu Dhabi	Munich
Barcelona	New Jersey
Brussels	New York
Chicago	Northern Virginia
Doha	Orange County
Dubai	Paris
Frankfurt	Rome
Hamburg	San Diego
Hong Kong	San Francisco
London	Shanghai
Los Angeles	Silicon Valley
Madrid	Singapore
Milan	Tokyo
Moscow	Washington, D.C.

          Re:BioMed Realty Trust, Inc.

Ladies and Gentlemen:

          We have acted as tax counsel to BioMed Realty Trust, Inc., a Maryland corporation (the “Company”), in connection with the registration by the Company of 5,000,000 shares of common stock of the Company, par value $0.01 per share, to be issued with respect to the Company’s dividend reinvestment and stock purchase plan, pursuant to: (i) a registration statement on Form S-3 dated September 4, 2009 (together with the documents incorporated by reference therein, the “Registration Statement”) filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”); and (ii) a related prospectus dated September 4, 2009 (the “Prospectus”).

          You have requested our opinion concerning certain of the federal income tax considerations relating to the Company. This opinion is based on various facts and assumptions, including the facts set forth in the Registration Statement and the Prospectus concerning the business, assets and governing documents of the Company, BioMed Realty, L.P. (the “Operating Partnership”) and their subsidiaries. We have also been furnished with, and with your consent have relied upon, certain representations made by the Company, the Operating Partnership and their subsidiaries with respect to various factual matters through a certificate of an officer of the Company, dated as of the date hereof (the “Officer’s Certificate”). With your permission, we have assumed that the conclusions reached in the opinion of Venable LLP, counsel for the Company, dated as of the date hereof, with respect to certain matters of Maryland law, are correct.

          In our capacity as tax counsel to the Company, we have made such legal and factual examinations and inquiries, including an examination of originals or copies certified or otherwise identified to our satisfaction of such documents, corporate records and other instruments as we have deemed necessary or appropriate for purposes of this opinion. For purposes of our opinion, we have not made an independent investigation or audit of the facts set forth in the above referenced documents or in the Officer’s Certificate. In addition, in rendering this opinion we have assumed the truth and accuracy of all representations and statements made to us which are qualified as to knowledge or belief, without regard to such qualification. In our examination, we have assumed the authenticity of all documents submitted to us as originals, the genuineness of all signatures thereon, the legal capacity of natural persons executing such documents and the conformity to authentic original documents of all documents submitted to us as copies.

BioMed Realty Trust, Inc.
September 4, 2009
Page 2

          We are opining herein only as to the federal income tax laws of the United States, and we express no opinion with respect to the applicability thereto, or the effect thereon, of other federal laws, the laws of any state or other jurisdiction or as to any matters of municipal law or the laws of any other local agencies within any state.

          Based on such facts, assumptions and representations, it is our opinion that:

          1. Commencing with its taxable year ending December 31, 2004, the Company has been organized and has operated in conformity with the requirements for qualification as a real estate investment trust (“REIT”) under the Internal Revenue Code of 1986, as amended (the “Code”), and its proposed method of operation will enable it to continue to meet the requirements for qualification and taxation as a REIT under the Code; and

          2. The statements set forth under the caption “Material United States Federal Income Tax Considerations” in the Prospectus, insofar as they purport to summarize certain provisions of the statutes or regulations referred to therein, are accurate summaries in all material respects.

          No opinion is expressed as to any matter not discussed herein.

          This opinion is rendered to you as of the date of this letter, and we undertake no obligation to update this opinion subsequent to the date hereof. This opinion is based on various statutory provisions, regulations promulgated thereunder and interpretations thereof by the Internal Revenue Service and the courts having jurisdiction over such matters, all of which are subject to change either prospectively or retroactively. Any such change may affect the conclusions stated herein. Also, any variation or difference in the facts from those set forth in the Registration Statement, the Prospectus or the Officer’s Certificate may affect the conclusions stated herein. As described in the Prospectus, the Company’s qualification and taxation as a REIT depend upon the Company’s ability to meet the various qualification tests imposed under the Code, including through actual annual operating results, asset composition, distribution levels and diversity of stock ownership, the results of which have not been and will not be reviewed by Latham & Watkins LLP. Accordingly, no assurance can be given that the actual results of the Company’s operation for any particular taxable year will satisfy such requirements.

          This opinion is rendered only to you and is solely for your benefit in connection with the Registration Statement. This opinion may not be relied upon by you for any other purpose, or furnished to, quoted to, or relied upon by any other person, firm, or other entity, for any purpose, without our prior written consent. We hereby consent to the filing of this opinion as an exhibit to the Registration Statement filed with the Commission as of the date hereof, and to the reference to our firm name in the Prospectus under the captions “Material United States Federal Income Tax Considerations” and “Legal Matters.” In giving this consent, we do not hereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the rules or regulations of the Commission promulgated thereunder.

Very truly yours,

/s/ Latham & Watkins LLP