SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                 --------------

                         POST-EFFECTIVE AMENDMENT NO. 1
                                       TO
                                    FORM S-3
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                 --------------
                               IMMUNOMEDICS, INC.
               (Exact name of registrant as specified in charter)

                Delaware                              61-1009366
   (State or other jurisdiction of       (I.R.S. Employer Identification No.)
    incorporation or organization)

                                300 American Road
                         Morris Plains, New Jersey 07950
                     Tel: (973) 605-8200 Fax: (973) 605-8282
       (Address, including zip code, and telephone number, including area
               code, of registrant's principal executive offices)

            Cynthia L. Sullivan, President & Chief Executive Officer
                               Immunomedics, Inc.
                                300 American Road
                         Morris Plains, New Jersey 07950
                     Tel: (973) 605-8200 Fax: (973) 605-8282
    (Name, address, including zip code, and telephone number, including area
                           code, of agent for service)

                                   Copies to:
                         Joseph E. Mullaney III, Esquire
               Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                              One Financial Center
                           Boston, Massachusetts 02111
                                 (617) 542-6000

        Approximate date of commencement of proposed sale to the public:
                                 Not Applicable.

     If the only  securities  being  registered  on this Form are being  offered
pursuant to dividend or interest  reinvestment plans, please check the following
box. |_|

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous  basis  pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment, check the following box. |_|

     If this Form is filed to  register  additional  securities  for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list  the  Securities  Act  registration  statement  number  of the  earlier
effective registration statement for the same offering. |_|

     If this Form is a  post-effective  amendment  filed pursuant to Rule 462(c)
under the  Securities  Act,  check the following box and list the Securities Act
registration  statement number of the earlier effective  registration  statement
for the same offering. |_|

     If delivery of the  prospectus is expected to be made pursuant to Rule 434,
please check the following box. |_|







                         DEREGISTRATION OF COMMON STOCK

     The Registrant  hereby amends its  Registration  Statement on Form S-3 (No.
333-94415),  initially  filed with the  Securities  and Exchange  Commission  on
January  11,  2000 (the "Form  S-3"),  by  deregistering  certain  shares of the
Registrant's common stock, par value $0.01 per share (the "Shares").  The Shares
to be deregistered  consist of all of the shares registered on the Form S-3 that
have not yet been sold by the selling  stockholders  and the holders of warrants
to sell Shares (collectively, the "Selling Stockholders").

     The  Registrant  initially  filed the Form S-3 to  register  the  following
shares issued to the selling stockholders:  (a) 2,500,000 shares of common stock
offered directly to the selling stockholders pursuant to a Common Stock Purchase
Agreement, dated December 14, 1999, by and among the Registrant and such Selling
Stockholders (the "Stock Purchase  Agreement");  and (b) 75,000 shares of common
stock  issuable  upon the exercise of a warrant  granted by the  Registrant to a
Selling  Stockholder  pursuant to a Warrant Agreement,  dated December 16, 1999.
The Registrant has filed prospectus  supplements under the Form S-3 from time to
time disclosing the identity of any underwriters,  dealers,  agents or investors
who have  purchased the Shares,  the material  terms of the  distributions,  the
amount  of  any   compensation,   discounts  or  commissions   received  by  the
underwriters,  dealers  or  agents,  and the  nature of any  market  stabilizing
transactions by such underwriters, dealers or agents.

     As of the date  hereof,  the  Registrant  has issued  all of the  2,575,000
shares of common stock  registered under the Form S-3.  However,  675,687 Shares
remain unsold by the Selling Stockholders (the "Remaining Shares").  Pursuant to
the  terms of the Stock  Purchase  Agreement,  the  Registrant's  obligation  to
maintain  the  effectiveness  of the  Form  S-3 has  expired.  Accordingly,  the
Registrant desires to deregister all of the Remaining Shares.

     Pursuant  to Rule 478  promulgated  under the  Securities  Act of 1933,  as
amended (the "Act"), and the undertaking  contained in this Form S-3 pursuant to
Item  512(a)(3) of  Regulation  S-K  promulgated  under the Act, the  Registrant
hereby  removes from  registration  the 675,687 Shares that remain unsold by the
Selling Stockholders as of the date hereof.




                                   SIGNATURES

     Pursuant to the  requirements of the Securities Act of 1933, the Registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing on Form S-3 and has duly  caused  this  Post-Effective
Amendment No. 1 to Registration Statement on Form S-3 to be signed on its behalf
by the  undersigned,  thereunto duly  authorized,  in the City of Morris Plains,
State of New Jersey, on April 29, 2002.

                                   IMMUNOMEDICS, INC.

                                   By   /S/ CYNTHIA L. SULLIVAN
                                        -----------------------------------
                                        Cynthia L. Sullivan
                                        President and Chief Executive Officer