PROSPECTUS SUPPLEMENT NO. 6                     Filed pursuant to Rule 424(b)(3)
(To prospectus dated October 24, 2001)                Registration No. 333-67506


                                  $400,000,000
                                   Enzon, Inc.

                 4 1/2% Convertible Subordinated Notes Due 2008
                                   ----------

This  Prospectus  Supplement No. 6 supplements  and amends the Prospectus  dated
October 24, 2001 relating to the 4 1/2% Convertible  Subordinated Notes due 2008
of  Enzon,  Inc.  and the  shares  of  common  stock  into  which  the notes are
convertible, at various times at market prices prevailing at the time of sale or
at privately negotiated prices.

The table on pages 38 through 40 of the prospectus, which sets forth information
with  respect  to the  selling  holders  and the  respective  amounts  of  notes
beneficially owned by each selling holder, is hereby amended as follows:

     The addition of the following:

     South Dakota Retirement System ................................ $2,500,000

The Prospectus,  together with  Prospectus  Supplement Nos. 1, 2, 3, 4 and 5 and
this  Prospectus  Supplement No. 6,  constitutes  the prospectus  required to be
delivered  by Section  5(b) of the  Securities  Act of 1933,  as  amended,  with
respect  to offers  and sales of the notes and the common  stock  issuable  upon
conversion of the notes.  All reference in the  prospectus to "this  prospectus"
are hereby amended to read "this prospectus (as supplemented and amended)".

Neither  the  Securities  and  Exchange  Commission  nor  any  state  securities
commission has approved or  disapproved  of these  securities or passed upon the
accuracy or adequacy of this prospectus. Any representation to the contrary is a
criminal offense.

            The date of this Prospectus Supplement is April 26, 2002.