Exhibit 99.1

PRESS RELEASE                          Contact:  Kenneth J. Zuerblis
                                                 Vice President, Finance & CFO
                                                 732-980-4717

                                       [Noonan/Russo Communications, Inc.
                                       212-696-4455
                                       Hala Bashir, Media Relations x356]


                  ENZON, INC. ADOPTS STOCKHOLDERS' RIGHTS PLAN

Piscataway, New Jersey; May 22, 2002 - Enzon, Inc. (Nasdaq: ENZN) announced
today that its board of directors adopted a rights plan under which its
stockholders of record on June 3, 2002 will receive a dividend payable in
preferred stock purchase rights.

The plan is designed to ensure that stockholders realize fair value and equal
treatment in the event of an attempted takeover of the company and to protect
the company and its stockholders against coercive takeover tactics. The plan was
not adopted in response to any efforts to acquire the company, and Enzon is not
aware of any such efforts. Each right will initially entitle stockholders to
purchase a fractional share of Enzon's preferred stock for $190. However, the
rights are not immediately exercisable and will become exercisable only upon the
occurrence of certain events. If a person or group acquires, or announces a
tender or exchange offer that would result in the acquisition of, 15 percent or
more of Enzon's common stock while the stockholder rights plan remains in place,
then, unless (1) the rights are redeemed by Enzon for $0.01 per right, or (2)
the board of directors determines that a tender or exchange offer for all of the
outstanding common stock of the company is in the best interest of the company
and the stockholders, then the rights will become exercisable by all rights
holders except the acquiring person or group for (1) shares of Enzon or (2) in
certain circumstances, shares of the third party acquirer, each having a value
of twice the right's then-current exercise price. Further details of the plan
are outlined in a letter that will be mailed to stockholders following the
record date.

Additionally, Enzon's board of directors approved and adopted several amendments
to Enzon's bylaws to provide for: (a) advance notice of stockholder proposals
and stockholder nominations for the election of directors; (b) a mandate that
the board of directors determine a record date for any action taken by a written
consent of the stockholders; and (c) verification of stockholder consents.

Except for the historical information herein, the matters discussed in this new
release include forward-looking statements that may involve a number of risks
and uncertainties. Actual results may vary significantly based upon a number of
factors which are described in the Company's Form 10-K, Form 10-K/A, Form 10-Qs
and Form 8-Ks on file with the SEC, including without limitation, risks in
obtaining and maintaining regulatory approval for indications and expanded
indications, risks that Enzon will not outperform the sector, market acceptance
of and continuing demand for Enzon's products and the impact of competitive
products and pricing.