[GRAPHIC OMITTED]

COMPANY CONTACT:
Cytogen Corporation
Stacy Shearer
Investor Relations
(609) 750-8289
sshearer@cytogen.com

                    CYTOGEN ANNOUNCES RESIGNATION OF DIRECTOR

PRINCETON,  N.J.,  (SEPTEMBER 3, 2004) -- Cytogen Corporation (NASDAQ:  CYTO), a
product-driven, oncology-focused biopharmaceutical company, today announced that
H. Joseph Reiser, Ph.D. has tendered his resignation from the Company's Board of
Directors, effective immediately. Dr. Reiser advised the Board of Directors that
he  was   resigning  his  position  in  order  to  focus  more  on  his  current
responsibilities and to further pursue certain personal interests.  Dr. Reiser's
resignation  letter  contained no disagreement  with  management  concerning any
matter relating to the Company's operations, policies or practices.

Dr. Reiser previously served as the Company's President, Chief Executive Officer
and Director from August 1998 until December  2002,  and thereafter  remained on
the Company's  Board of Directors to provide  continuity  to the new  management
team.

James A. Grigsby, Chairman of the Company's Board of Directors, stated that "Joe
Reiser  has  been  instrumental  in  building  Cytogen  into  a  product-driven,
oncology-focused  organization  over the past six years and the Board recognizes
Joe's  long  standing  commitment  to the  Company  and  its  stockholders.  His
willingness  to  serve on the  Board  during  this  transition  period  has been
enormously helpful."

ABOUT CYTOGEN CORPORATION

Founded in 1980,  Cytogen  Corporation  of  Princeton,  NJ is a  product-driven,
oncology-focused  biopharmaceutical  company that develops and  commercializes a
balanced  portfolio of oncology products that address the unmet medical needs of
patients  and  the  physicians  that  serve  them.   Cytogen   directly  markets
QUADRAMET(TM) (samarium Sm-153 lexidronam injection),  PROSTASCINT(R)  (capromab
pendetide) kit for the  preparation  of Indium In-111  capromab  pendetide,  and
NMP22(R)  BLADDERCHEK(R)  (nuclear  matrix  protein-22)  in the  United  States.
Cytogen  has  exclusive   United   States   marketing   rights  to   COMBIDEX(R)
(ferumoxtran-10),  an investigational molecular imaging agent consisting of iron
oxide  nanoparticles  for use in conjunction with magnetic  resonance imaging to
aid in the  differentiation of cancerous and non-cancerous lymph nodes, which is
under  review  by the  U.S.  Food  and  Drug  Administration.  Cytogen  is  also
developing therapeutics targeting  prostate-specific  membrane antigen (PSMA), a
protein  highly  expressed  on the  surface  of  prostate  cancer  cells and the
neovasculature of solid tumors.  Full prescribing  information for the Company's
products is available at www.cytogen.com or by calling 1-800-833-3533.  For more
information, please visit the Company's website at www.cytogen.com, which is not
part of this press release.

THIS PRESS RELEASE  CONTAINS  CERTAIN  "FORWARD-LOOKING"  STATEMENTS  WITHIN THE
MEANING OF THE PRIVATE SECURITIES  LITIGATION REFORM ACT OF 1995 AND SECTION 21E
OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.  ALL STATEMENTS,  OTHER THAN
STATEMENTS OF  HISTORICAL  FACTS,  INCLUDED IN THIS PRESS RELEASE  REGARDING OUR
STRATEGY,  FUTURE OPERATIONS,  FINANCIAL  POSITION,  FUTURE REVENUES,  PROJECTED
COSTS,  PROSPECTS,  PLANS  AND  OBJECTIVES  OF  MANAGEMENT  ARE  FORWARD-LOOKING
STATEMENTS.  SUCH  FORWARD-LOOKING  STATEMENTS  INVOLVE  A NUMBER  OF RISKS  AND
UNCERTAINTIES  AND INVESTORS ARE CAUTIONED NOT TO PUT ANY UNDUE  RELIANCE ON ANY
FORWARD-LOOKING  STATEMENT.



THERE ARE A NUMBER OF IMPORTANT  FACTORS THAT COULD CAUSE  CYTOGEN'S  RESULTS TO
DIFFER MATERIALLY FROM THOSE INDICATED BY SUCH  FORWARD-LOOKING  STATEMENTS.  IN
PARTICULAR,  CYTOGEN'S  BUSINESS  IS SUBJECT TO A NUMBER OF  SIGNIFICANT  RISKS,
WHICH  INCLUDE,  BUT ARE NOT LIMITED  TO: THE RISK OF  OBTAINING  THE  NECESSARY
REGULATORY  APPROVALS;  THE RISK OF WHETHER  PRODUCTS  RESULT  FROM  DEVELOPMENT
ACTIVITIES;  THE RISK OF SHIFTS IN THE REGULATORY ENVIRONMENT AFFECTING SALES OF
CYTOGEN'S  PRODUCTS SUCH AS THIRD-PARTY  PAYOR  REIMBURSEMENT  ISSUES;  THE RISK
ASSOCIATED WITH CYTOGEN'S  DEPENDENCE ON ITS PARTNERS FOR DEVELOPMENT OF CERTAIN
PROJECTS,  AS WELL AS OTHER  FACTORS  EXPRESSED  FROM TIME TO TIME IN  CYTOGEN'S
PERIODIC FILINGS WITH THE SECURITIES AND EXCHANGE  COMMISSION (THE "SEC").  AS A
RESULT, THIS PRESS RELEASE SHOULD BE READ IN CONJUNCTION WITH CYTOGEN'S PERIODIC
FILINGS WITH THE SEC. THE FORWARD-LOOKING  STATEMENTS  CONTAINED HEREIN ARE MADE
ONLY AS OF THE DATE OF THIS PRESS RELEASE,  AND CYTOGEN UNDERTAKES NO OBLIGATION
TO PUBLICLY UPDATE SUCH FORWARD-LOOKING  STATEMENTS TO REFLECT SUBSEQUENT EVENTS
OR CIRCUMSTANCES.

                                       ###