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                                                                   Exhibit 5.1


                                         February 11, 2000





SL Green Realty Corp.
420 Lexington Avenue
New York, NY 10170

Ladies and Gentlemen:

     This opinion is furnished in connection with the registration statement
on Form S-3 (the "Registration Statement"), pursuant to the Securities Act of
1933, as amended (the "Securities Act"), relating to the offering from time
to time by selling shareholders of up to 1,173,232 shares of Common Stock (as
such terms are defined in the Registration Statement), of SL Green Realty
Corp., a Maryland corporation (the "Company").

     In connection with rendering this opinion, we have examined the
Company's Amended and Restated Articles of Incorporation, and the Bylaws, as
amended, of the Company; such records of the corporate proceedings of the
Company as we deemed appropriate; the Registration Statement, and such other
certificates, receipts, records and documents as we considered necessary for
the purposes of this opinion.

     We express no opinion concerning the laws of any jurisdictions other
than the laws of the United States of America, the State of Maryland and the
State of New York.

     Based upon the foregoing, we are of the opinion that:


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          The shares of Common Stock have been duly authorized, validly
issued, fully paid and nonassessable.

     The foregoing assumes that all requisite steps will be taken to comply
with the requirements of the Securities Act and applicable requirements of
state laws regulating the offer and sale of securities.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and the reference to our firm under the caption "Legal
Matters" in the Prospectus.


                                         Very truly yours,

                                         /s/ Brown & Wood LLP

