Exhibit 5.1

McDermott, Will & Emery

                                             June 12, 2002




GlycoGenesys, Inc.
31 St. James Avenue, 8th Floor
Boston, MA  02116

     Re: Registration Statement on Form S-3

Dear Ladies & Gentlemen:

     At your request, we have examined the form of Registration Statement on
Form S-3, as amended (the "Registration Statement"), filed by GlycoGenesys,
Inc., a Nevada corporation (the "Company"), with the Securities and Exchange
Commission in connection with the registration for resale under the Securities
Act of 1933, as amended, of an aggregate of up to 13,069,763 shares of Common
Stock, par value $.01 per share, of the Company (the "Common Stock")
representing: (i) an aggregate of 6,723,181 shares of Common Stock issued in
private placements by the Company completed in December 2001 and January 2002
(collectively, the "Private Placements"); (ii) 243,167 shares of Common Stock
issued to placement agents in connection with the Private Placements (the shares
in clause (i) and (ii), the "Outstanding Shares"); (iii) an aggregate of
4,905,312 shares of Common Stock issuable upon exercise of warrants issued in
the Private Placements; (iv) an aggregate of 385,603 shares of Common Stock
issuable upon exercise of warrants issued to the placement agents in connection
with the Private Placements; and (v) a total of 812,500 shares of Common Stock
issuable upon exercise of warrants issued to Wayne State University and the
Barbara Ann Karmanos Cancer Institute (the shares in clause (iii), (iv) and (v),
the "Warrant Shares").

     We understand that the Outstanding Shares and Warrant Shares may be sold
from time to time for the account of certain stockholders of the Company.

     We have examined the proceedings heretofore taken by the Company in
connection with the authorization, issuance and sale of the Outstanding Shares
and the Warrant Shares.

     Based on the foregoing, and assuming that the full consideration for each
of the Warrant Shares is received by the Company in accordance with the terms of
the applicable warrants, it is our opinion that the Outstanding Shares covered
by the Registration Statement are, and the Warrant Shares when issued, will be
validly issued, fully paid and nonassessable.

     We consent to the use of this opinion as an exhibit to the Registration
Statement and to the use of our name under the caption "Legal Matters" in the
Prospectus which is part of the Registration Statement.



                                             Very truly yours,


                                             /s/ McDermott, Will & Emery