Exhibit 5



                                March 19, 1999

Boston Life Sciences, Inc.
31 Newbury Street
Suite 300
Boston, MA 02116

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

Gentlemen:

          We have acted as special counsel to Boston Life Sciences, Inc. (the
"Company") in connection with the registration under the Securities Act of 1933,
as amended, of 2,582,677 shares of common stock of the Company, par value $.01
per share (the "Shares"), proposed to be sold by certain Selling Stockholders
named in the Registration Statement on Form S-3 (the "Registration Statement").

          In rendering our opinion, we have reviewed and relied upon such
certificates, documents, corporate records and other instruments as in our
judgment are necessary or appropriate to enable us to render the opinion
expressed below.  In giving this opinion, we are assuming the authenticity of
all instruments presented to us as originals, the conformity with the originals
of all instruments presented to us as copies and the genuineness of all
signatures.

          Based on the foregoing, we are of the opinion that the Shares to be
sold by the Selling Stockholders have been duly authorized and, when duly
executed, delivered, issued and paid for, will be legally issued, fully paid and
nonassessable.

          We consent to the filing of this opinion as Exhibit 5 to the
Registration Statement with respect to the offering of the Shares and the
reference to the firm in the section of the Registration Statement entitled
"Legal Matters."

          This opinion is limited to the matters expressly stated herein.  No
implied opinion may be inferred to extend this opinion beyond the matters
expressly stated herein.  We do not undertake to advise you or anyone else of
any changes in the opinions expressed herein resulting from changes in law,
changes in facts or any other matters that hereafter might occur or be brought
to our attention.

                              Very truly yours,


                              /s/ Ballard Spahr Andrews & Ingersoll, LLP