As filed with the Securities and Exchange Commission on June 28, 2004
                      Registration Statement No. 333-59718

                              WASHINGTON, DC 20549

                        POST-EFFECTIVE AMENDMENT NO. 1 TO
                                    FORM S-8

                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                               CYTOGEN CORPORATION
             (Exact Name of Registrant as Specified in Its Charter)

            Delaware                                            22-2322400
---------------------------------                       ------------------------
  (State or Other Jurisdiction                               (I.R.S. Employer
of Incorporation or Organization)                         Identification Number)

                        650 College Road East, 3rd Floor
                           Princeton, New Jersey 08540
                                 (609) 750-8200
          (Address, Including Zip Code, and Telephone Number, Including
             Area Code, of Registrant's Principal Executive Offices)

                            Donald L. Novajosky, Esq.
                                 Director, Legal
                               Cytogen Corporation
                        650 College Road East, 3rd Floor
                           Princeton, New Jersey 08540
                                 (609) 750-8222
            (Name, Address, Including Zip Code, and Telephone Number,
                   Including Area Code, of Agent for Service)

                                    COPY TO:

                             William J. Thomas, Esq.
                    Wilmer Cutler Pickering Hale and Dorr LLP
                        650 College Road East, 4th Floor
                           Princeton, New Jersey 08540
                                 (609) 750-7600


                              EXPLANATORY STATEMENT

         On  April  27,  2001,  Cytogen  Corporation  (the  "Company")  filed  a
registration  statement  on Form S-8 (File No.  333-59718)  to register  200,000
shares of the  Company's  Common  Stock,  par value $0.01 per share (the "Common
Stock") for issuance in connection  with the Company's  Retirement  Savings Plan
(the "Savings Plan").

         Pursuant to Item  512(a)(3)  of  Regulation  S-K,  this  Post-Effective
Amendment No. 1 to Form S-8 is being filed in order to  deregister  and withdraw
from  registration  all shares of the Company's  Common Stock and plan interests
remaining  unsold  under  Registration  Statement  No.  333-59718 as of the date

         Based on the Company's  review of Section 3(a)(2) of the Securities Act
of 1933,  and the rules and  regulations  promulgated  thereunder,  the  Company
believes  registration  of the Common Stock and plan  interests  relating to the
Savings Plan is no longer necessary.


         Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the  requirements  for  filing  on  Form  S-8 and has  duly  caused  this
Amendment  to the  Registration  Statement  to be  signed  on its  behalf by the
undersigned,  thereunto duly authorized, in the City of Princeton,  State of New
Jersey, on June 28, 2004.

                               CYTOGEN CORPORATION

                               By:  /s/ Michael D. Becker
                                    Michael D. Becker
                                    President and Chief Executive Officer

                        SIGNATURES AND POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS,  that each  individual  whose signature
appears below  constitutes  and appoints  Michael D. Becker and  Christopher  P.
Schnittker,  and each of them, his true and lawful  attorneys-in-fact and agents
with full power of  substitution  and  resubstitution,  for him and in his name,
place  and  stead,  in any and all  capacities,  to sign any and all  amendments
(including  post-effective  amendments) to this Registration  Statement,  and to
file the  same  with all  exhibits  thereto,  and all  documents  in  connection
therewith,  with the  Securities  and Exchange  Commission,  granting  unto said
attorneys-in-fact  and agents,  and each of them, full power and authority to do
and perform each and every act and thing  requisite  and necessary to be done in
and about the  premises,  as fully to all  intents  and  purposes as he might or
could  do  in  person,   hereby   ratifying   and   confirming   all  that  said
attorneys-in-fact  and  agents  or any of them,  or their or his  substitute  or
substitutes, may lawfully do or cause to be done by virtue hereof.

         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement  has  been  signed  by  the  following  persons  in  the
capacities and on the dates indicated.

             SIGNATURE                                   TITLE                         DATE
------------------------------------  ------------------------------------------  --------------

/s/ Michael D. Becker                 President, Chief Executive Officer and      June 28, 2004
------------------------------------  Director (Principal Executive Officer)
Michael D. Becker

/s/ Christopher P. Schnittker         Senior Vice President and Chief
------------------------------------  Financial Officer (Principal Financial
Christopher P. Schnittker             and Accounting Officer)                     June 28, 2004

/s/ John E. Bagalay, Jr.              Director
John E.  Bagalay, Jr.                                                             June 25, 2004

/s/ Allen Bloom                       Director
Allen Bloom                                                                       June 24, 2004

/s/ Stephen K. Carter                 Director
Stephen K. Carter                                                                 June 23, 2004

/s/ James A. Grigsby                  Director
James A. Grigsby                                                                  June 28, 2004

/s/ Robert F. Hendrickson             Director
Robert F. Hendrickson                                                             June 21, 2004

/s/ Kevin G. Lokay                    Director
Kevin G. Lokay                                                                    June 22, 2004

/s/ H. Joseph Reiser                  Director
H. Joseph Reiser                                                                  June 22, 2004