Exhibit 5
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                                Bingham Dana LLP
                               150 Federal Street
                                Boston, MA 02110

                                October 15, 1998

LeukoSite, Inc.
215 First Street
Cambridge, Massachusetts 02142

         Re: Registration Statement on Form S-3 Under the Securities
             Act of 1933, as amended

Ladies and Gentlemen:

         We have acted as counsel to LeukoSite, Inc., a Delaware corporation
(the "Company"), in connection with the registration under the Securities Act of
1933, as amended (the "Act"), of 7,071,810 shares (the "Shares") of the
Company's Common Stock, $0.01 par value per share, to be offered by certain
stockholders of the Company (the "Selling Stockholders"), pursuant to a
Registration Statement on Form S-3, initially filed by the Company with the
Securities and Exchange Commission on October 15, 1998.

         As such counsel, we have reviewed the corporate proceedings taken by
the Company with respect to the authorization of the issuance of the Shares. We
have also examined and relied upon originals or copies, certified or otherwise
authenticated to our satisfaction, of such corporate records, documents,
agreements or other instruments of the Company. As to all matters of fact
(including factual conclusions and characterizations and descriptions of
purpose, intention or other state of mind) we have entirely relied upon
certificates of officers of the Company, and have assumed, without independent
inquiry, the accuracy of those certificates.

         We have assumed the genuineness of all signatures, the conformity to
the originals of all documents reviewed by us as copies, the authenticity and
completeness of all original documents reviewed by us in original or copy form
and the legal competence of each individual executing a document. We have also
assumed that the registration requirements of the Act and all applicable





requirements of state laws regulating the sale of securities will have been duly
satisfied.

         With respect to our opinion set forth below with respect to the Shares,
we have assumed that the Company has received the specified purchase price
therefor.

         This opinion is limited solely to the Delaware General Corporation Law
as applied by courts located in the State of Delaware.

         Subject to the foregoing, it is our opinion that the Shares have been
duly authorized, validly issued and fully paid and are non-assessable.

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

                                Very truly yours,

                                /s/ Bingham Dana LLP

                                Bingham Dana LLP

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