SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                   FORM 12b-25

                                                Commission File Number 000-14879
                                                CUSIP Number 232824300

                           NOTIFICATION OF LATE FILING

     (Check One): |_| Form 10-K  |_| Form 20-F  |_| Form 11-K  |X| Form 10-Q
|_| Form 10-D  |_|Form N-SAR  |_| Form N-CSR

     For Period Ended:      September 30, 2005
                      ----------------------------------------------------------

|_|  Transition Report on Form 10-K
|_|  Transition Report on Form 20-F
|_|  Transition Report on Form 11-K
|_|  Transition Report on Form 10-Q
|_|  Transition Report on Form N-SAR

     For the Transition Period Ended:
                                     -------------------------------------------

     Read attached  instruction  sheet before  preparing  form.  Please print or
type.

     Nothing in this form shall be  construed to imply that the  Commission  has
verified any information contained herein.

     If the  notification  relates  to a portion of the  filing  checked  above,
identify the item(s) to which the notification relates:


                                     PART I
                             REGISTRANT INFORMATION

Full name of Registrant                  Cytogen Corporation
                       ---------------------------------------------------------

Former name if applicable
                         -------------------------------------------------------

Address of principal executive office (Street and Number) 650 College Road East
                                                         -----------------------

City, state and zip code             Princeton, New Jersey 08540
                        --------------------------------------------------------


                                     PART II
                             RULE 12b-25 (b) AND (c)

     If the subject report could not be filed without unreasonable effort or
expense and the registrant seeks relief pursuant to Rule 12b-25(b), the
following should be completed. (Check box if appropriate.)





          (a)  The reasons  described in  reasonable  detail in Part III of this
               form  could  not be  eliminated  without  unreasonable  effort or
               expense;

     |X|  (b)  The subject annual report,  semi-annual report, transition report
               on Form 10-K,  Form 20-F, Form 11-K, Form N-SAR or Form N-CSR, or
               portion thereof, will be filed on or before the 15th calendar day
               following  the  prescribed  due date;  or the  subject  quarterly
               report or transition report on Form 10-Q or subject  distribution
               report  on Form  10-D, or  portion thereof,  will be  filed on or
               before  the fifth calendar day following the prescribed due date;
               and

          (c)  The  accountant's  statement  or other  exhibit  required by Rule
               12b-25(c) has been attached if applicable.


                                    PART III
                                    NARRATIVE

     State below in  reasonable  detail the reasons why Form 10-K,  20-F,  11-K,
10-Q, 10-D, N-SAR, N-CSR, or the transition report portion thereof, could not be
filed within the prescribed time period.

     The Company is unable to timely file its Quarterly  Report on Form 10-Q for
the Quarter  Ended  September  30, 2005 (the "Form 10-Q")  without  unreasonable
effort or expense.  The management of the Company has been utilizing much of its
recent efforts in determining the accounting  treatment for warrants to purchase
common  stock  issued in July 2005 and August  2005.  The Form 10-Q is currently
being  prepared and will be filed no later than the fifth calendar day following
the November 9, 2005 due date of the Form 10-Q.


                                     PART IV
                                OTHER INFORMATION

     (1)  Name and  telephone  number of  person  to  contact  in regard to this
notification

          Christopher P. Schnittker         609                 750-8205
        ------------------------------------------------------------------------
                   (Name)               (Area Code)        (Telephone Number)


     (2)  Have all other periodic reports  required under Section 13 or 15(d) of
the Securities  Exchange Act of 1934 or Section 30 of the Investment Company Act
of 1940  during the  preceding  12 months or for such  shorter  period  that the
registrant was required to file such report(s) been filed?  If the answer is no,
identify report(s).

                                        |X|  Yes      |_| No

     (3)  Is it anticipated that any significant change in results of operations
from the corresponding  period for the last fiscal year will be reflected by the
earnings statements to be included in the subject report or portion thereof?

                                        |X|  Yes      |_| No

     If so: attach an explanation of the anticipated  change,  both  narratively
and  quantitatively,  and, if  appropriate,  state the reasons why a  reasonable
estimate of the results cannot be made.





                               Cytogen Corporation
--------------------------------------------------------------------------------
                  (Name of Registrant as Specified in Charter)

has  caused  this  notification  to be signed on its  behalf by the  undersigned
thereunto duly authorized.

                                 CYTOGEN CORPORATION



Date: November 9, 2005           By:  /s/ Christopher P. Schnittker
                                    --------------------------------------------
                                    Christopher P. Schnittker
                                    Senior Vice President and
                                       Chief Financial Officer
                                    (Principal Financial and Accounting Officer)





                                    EXHIBIT A

                                     PART IV

                                OTHER INFORMATION

For the three months ended  September  30, 2005,  the Company  expects to report
total revenue of $3,551,000,  an increase of $290,000 from revenue of $3,261,000
in the  comparable  quarter last year.  For the nine months ended  September 30,
2005, the Company expects to report total revenue of $11,701,000, an increase of
$887,000 from revenue of  $10,814,000  in the  comparable  period last year. The
Company  now  expects to report that net loss and net loss per basic and diluted
share,  for the  three  and  nine  months  ended  September  30,  2005,  will be
materially  less than it had  previously  announced  on November  2, 2005.  Such
change  is due to a  non-cash  gain in the value of the  warrants  issued by the
Company  in July  2005  and  August  2005.  The  Company  is in the  process  of
performing  a  Black-Scholes  valuation  analysis  on such  warrants  and cannot
currently reasonably  estimate  the revised  net loss and net loss per basic and
diluted share for the three and nine months ended September 30, 2005.