Exhibit 99.1


       ENZON, INC. RAISES AN ADDITIONAL $12.5 MILLION THROUGH EXERCISE OF
                              OVER-ALLOTMENT OPTION

Piscataway,  New Jersey, March 24, 2000 - Enzon, Inc., (NASDAQ:  ENZN) announced
today that the  underwriters of the Company's  recent public offering have fully
exercised  their  over-allotment  option by purchasing  300,000 shares of common
stock  from the  Company  at $44.50  per  share.  As a result,  Enzon  raised an
additional  $12.5 million in net proceeds.  Total net proceeds to Enzon from the
offering,  including  the  exercise of the  over-allotment  option,  amounted to
approximately $95.7 million,  through the sale of a total of 2,300,000 shares of
common stock. The managing underwriters for the offering are Morgan Stanley Dean
Witter, CIBC World Markets and SG Cowen Securities Corporation.

A  registration  statement  relating  to these  securities  was  filed  with and
declared effective by the Securities and Exchange Commission. This press release
shall not constitute an offer to sell or a  solicitation  of an offer to buy nor
shall  there be any sale of these  securities  in any state in which such offer,
solicitation or sale would be unlawful prior to  registration  or  qualification
under the securities laws of such state.

A copy of the  Prospectus  relating to the offering may be obtained  from Morgan
Stanley Dean Witter, Attn: Prospectus  Department,  1585 Broadway, New York, New
York, 10036-8293,  when available. The registration statement can also be viewed
on the Internet at http://www.sec.gov.