EXHIBIT 99.1

                CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350








                CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,

                             AS ADOPTED PURSUANT TO

                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

         In  connection  with  the  Quarterly  Report  on Form  10-Q of  Cytogen
Corporation  (the  "Company")  for the period ended March 31, 2003 as filed with
the Securities and Exchange  Commission on the date hereof (the  "Report"),  the
undersigned,  Michael D. Becker,  President and Chief  Executive  Officer of the
Company,  and Thu Dang, Vice  President,  Finance,  of the Company,  each hereby
certifies, pursuant to 18 U.S.C. Section 1350, that:

     (1) The Report fully  complies  with the  requirements  of Section 13(a) or
15(d) of the Securities Exchange Act of 1934; and

     (2) The  information  contained  in the  Report  fairly  presents,  in all
material  respects,  the  financial  condition  and results of operations of the
Company.

         A signed original of this written statement required by Section 906 has
been provided to Cytogen Corporation and will be retained by Cytogen Corporation
and  furnished  to the  Securities  and  Exchange  Commission  or its staff upon
request.


                                       /s/ Michael D. Becker
                                       -----------------------------------------
Dated:   May 14, 2003                  Michael D. Becker
                                       President and Chief Executive Officer


                                       /s/ Thu Dang
                                       -----------------------------------------
Dated:    May 14, 2003                 Thu Dang
                                       Vice President, Finance