EXHIBIT 10.39


[LOGO OF CYTOGEN APPEARS HERE]


                                        December 20, 1996



Graham S. May, M.D.
151 Mine Mount Road
Bernardsville, NJ 07924

Dear Dr. May:

     CYTOGEN Corporation is pleased to offer you the position of
Vice President, Medical Affairs at an annualized salary of
$213,000.  This position is eligible for participation in the
Management Group Bonus Plan.  While the amount of this bonus is
determined each year by the Board, the range for this is 0-25% of
annual salary.  Your employment will begin no later than February
1, 1997.  You will report to Dr. Thomas J. McKearn, Chairman,
President and CEO.

     As a CYTOGEN employee, you are entitled to comprehensive
medical, dental, life AD&D, long-term disability, and travel and
accident coverage.  Dependent medical and dental coverage is also
available.  Employees contribute 20% towards the cost of the
premiums for medical and dental benefits.  This amount is deducted
through payroll on a pre-tax basis.  The total benefit package
becomes effective on the first day of your employment.  You will be
entitled to four weeks of paid vacation in your first year with the
Company.

     We will also recommend to the Board of Directors that you be
granted an option to purchase 45,000 shares of CYTOGEN Common
Stock.  Granting stock options requires the approval of the Board
of the Directors, following which will be issued your stock option
agreement.

     The Vice President, Medical Affairs sits on the Management
Committee of CYTOGEN Corporation and as such is provided with an
Executive Secretary.  The Company will pay you a monthly car
allowance of $550.00 and will also pay the insurance and routine
maintenance expenses for the car.  Management Committee members
also receive reimbursement of expenses incurred for financial
planning and/or tax preparation in amounts up to $5,000.00 per
year.

     It is understood that you will need to devote some time to the
orderly termination of affairs pertaining to your position with
your current employer.  CYTOGEN is willing to cooperate in this 
process by providing you with release time - as needed - up until
February 14, 1997 to complete this transition.

     As discussed, it is agreed that you may continue to engage as
a Medical Consultant with Smiths Industries, provided there is no
conflict of interest with your activities at CYTOGEN and does not
impact your performance at CYTOGEN.

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     In the event of discharge from duties for reasons other than
just cause (e.g., fraud, criminal or willful misconduct) then you
shall receive twelve months of pay in accordance with past Company
practices.

     Federal law requires the completion of the attached form (I-9)
and our examination of original documentation from list A or from
both list B and C.  In order to facilitate your employment, you
should complete Part 1 of the attached form and bring it with the
necessary supporting documentation to orientation.  You will also
be required to sign CYTOGEN's Secrecy Agreement and Photo Consent
Release forms enclosed and bring them with you on your first day of
employment.

     You will be required to schedule a pre-employment physical and
should contact Rebecca Bucci, Manager of Employment, at (609)987-8289 
to set up a mutually agreeable time for your pre-employment
physical.  This offer of employment is contingent on your passing
the pre-employment physical and a drug screening test.

     Please indicate your acceptance of this offer by signing below
and returning the original to my attention.  This offer will be
considered null and void if a signed copy is not returned within 10
business days of the date of this letter.  We look forward to you
joining us.

                                             Sincerely



/s/ Kim M. Moffa                            /s/ Thomas J. McKearn, M.D., Ph.D.
--------------------                        -----------------------------------
    Kim M. Moffa                                Thomas J. McKearn, M.D., Ph.D.
    Director, Human Resources                   Chairman, President & CEO



ACCEPTED AND AGREED TO THIS 27th DAY OF DECEMBER, 1996
                            ----        --------

BY:   /s/ Graham S. May, M.D.  
      -----------------------
        Graham S. May, M.D.     


cc:  C.E. Austin
     R. Brenner
     D. O'Neill


enc


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