As filed with the Securities and Exchange Commission on September 30, 1998

                                                   Registration No.
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                               ------------------

                                    FORM S-8

             REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                          IMCLONE SYSTEMS INCORPORATED
             (Exact name of registrant as specified in its charter)

             Delaware                                            04-2834797
  (State or other jurisdiction of                             (I.R.S. Employer
  incorporation or organization)                             Identification No.)

             180 Varick Street
            New York, New York                                      10014
 (Address of Principal Executive Offices)                        (Zip Code)

  ImClone Systems Incorporated 1998 Non-Qualified Stock Option Plan, As Amended
         ImClone Systems Incorporated 1998 Employee Stock Purchase Plan
                Option to Purchase 60,000 Shares of Common Stock
                            (Full title of the plan)

                               ------------------

                                 John B. Landes
            Vice President, Business Development and General Counsel
                          ImClone Systems Incorporated
                                180 Varick Street
                            New York, New York 10014
                     (Name and address of agent for service)

                                 (212) 645-1405
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                           Lawrence A. Darby III, Esq.
                   Kaye, Scholer, Fierman, Hays & Handler, LLP
                                 425 Park Avenue
                          New York, New York 10022-3598

                         CALCULATION OF REGISTRATION FEE

================================================================================
Title of       Amount          Proposed maximum Proposed maximum    Amount of
securities to  to be           offering price   aggregate           registration
be registered  registered(1)   per share(2)     offering price(2)   fee
--------------------------------------------------------------------------------
Common Stock, 
$.001 par      
value .......    637,000          $11.44          $7,287,280         $2,150
                 363,000            9.625          3,493,875          1,031
                 500,000            9.625          4,812,500          1,420
                  60,000           10.125            607,500            180
--------------------------------------------------------------------------------
  Totals ....  1,560,000                         $16,201,155         $4,781
================================================================================

----------
(1)   Excludes such additional indeterminate number of shares as may be issuable
      pursuant to the anti-dilution  provisions of the Plans (as defined) or the
      Martell Option (as defined). This total represents (i) 1,000,000 shares of
      Common  Stock and 500,000  shares of Common  Stock  reserved  for issuance
      pursuant  to options  granted or which may be  granted  under the  ImClone
      Systems Incorporated 1998 Non-Qualified Stock Option Plan, As Amended, and
      the ImClone  Systems  Incorporated  1998  Employee  Stock  Purchase  Plan,
      respectively  (together,  the  "Plans")  and (ii) 60,000  shares of Common
      Stock reserved for  issuance to the Company's,  Vice President, Marketing,
      pursuant to a certain Option Agreement dated as of September 1, 1998.

(2)   Estimated  solely for the purposes of calculating  the  registration  fee.
      Pursuant to Rule 457(c) and Rule 457(h) under the  Securities Act of 1933,
      as amended, the proposed maximum offering price per share and the proposed
      maximum aggregate offering price of shares subject to outstanding  options
      have been  determined on the basis of the average  exercise  prices of the
      outstanding  options and shares not subject to  outstanding  options  have
      been  determined  based on the  average  of the high and low prices of the
      Common Stock on September  29,  1998,  as reported by the NASDAQ  National
      Market.

<PAGE>

                            SECTION 10(a) PROSPECTUS

      The  documents  containing  the  information  specified  in Part I of this
Registration  Statement on Form S-8 will be sent or given to participants in the
Plans as  specified  by Rule  428(b)(i)  under the  Securities  Act of 1933,  as
amended.  Such documents are not required to be, and are not being, filed by the
Company  with the  Securities  and Exchange  Commission,  either as part of this
Registration  Statement or as prospectuses or prospectus supplements pursuant to
Rule 424 under the Securities Act of 1933, as amended. Such documents,  together
with the documents  incorporated by reference  herein pursuant to Item 3 of Part
II of this  Registration  Statement on Form S-8,  constitute  a prospectus  that
meets the  requirements  of  Section  10(a) of the  Securities  Act of 1933,  as
amended.


                                       2
<PAGE>

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

      The  following  documents  which  have  heretofore  been  filed by ImClone
Systems  Incorporated,   a  Delaware  corporation  (the  "Company"),   with  the
Securities and Exchange Commission (the "Commission") pursuant to the Securities
Exchange Act of 1934,  as amended (the  "Exchange  Act"),  are  incorporated  by
reference herein and shall be deemed to be a part hereof:

1.   The Company's Annual Report on Form 10-K for the fiscal year ended December
     31, 1997.

2.   The Company's  Quarterly Reports on Form 10-Q for the fiscal quarters ended
     March 31, 1998 and June 30, 1998.

3.   The  Company's  Current  Report on Form 8-K filed  with the  Commission  on
     February 10, 1998.

4.   The description of the Company's  Common Stock,  par value $.001 per share,
     contained  in its  Registration  Statement  on Form  8-A  filed  under  the
     Exchange  Act,  including  any amendment or report filed for the purpose of
     updating such description.

      All other documents  filed by the Company with the Commission  pursuant to
Sections  13(a),  13(c), 14 and 15(d) of the Exchange Act subsequent to the date
of this  Registration  Statement  and prior to the  filing  of a  post-effective
amendment to this  Registration  Statement  which  indicates that all securities
offered  have been sold or which  de-registers  all  securities  then  remaining
unsold,  shall be deemed to be  incorporated  by reference in this  Registration
Statement  and to be a part  hereof  from the date of filing  of such  documents
(such documents,  and the documents enumerated above, being hereinafter referred
to collectively as the "Incorporated Documents").

      Any statement contained in an Incorporated  Document shall be deemed to be
modified or superseded for purposes of this Registration Statement to the extent
that  a  statement   contained  therein  or  in  any  other  subsequently  filed
Incorporated Document modifies or supersedes such statement. Any such statements
so  modified  or  superseded  shall  not be  deemed,  except as so  modified  or
superseded, to constitute a part of this Registration Statement.

Item 4. Description of Securities.

      Not applicable.

Item 5. Interest of Named Experts and Counsel.

      Not applicable.

Item 6. Indemnification of Directors and Officers.

      The Company's Certificate of Incorporation and Bylaws set forth the extent
to which  officers and directors of the Company may be  indemnified  against any
liabilities which they may incur. The general effect of such provisions is that,
on  the  terms  and  conditions  set  forth  in  the  Company's  Certificate  of
Incorporation  and Bylaws,  any person made a party or  threatened  to be made a
party to an action,  suit or  proceeding by reason of the fact that he or she is
or was a director or officer of the Company, or is or was serving as a director,
officer,  employee or agent of another  corporation  or other  enterprise at the
request of the Company,  shall be  indemnified by the Company  against  expenses
(including  attorneys'  fees,  judgments,  fines and amounts paid in settlement)
reasonably  incurred or suffered by him or her in  connection  with such action,
suit or proceeding,  to the full extent permitted under the laws of the State of
Delaware;  provided,  however, that, subject to certain limited exceptions,  the
Company shall  indemnify any such person 


                                       3
<PAGE>

seeking indemnification in connection with a proceeding initiated by such person
only if such proceeding was authorized by the Board of Directors of the Company.
The Company's  Certificate of Incorporation  gives the Board of Directors of the
Company the  authority to extend such  indemnification  to  employees  and other
agents of the Company as well.

      The general effect of the indemnification  provisions contained in Section
145 of the General  Corporation  Law of the State of Delaware (the "DGCL") is as
follows:  A  director  or  officer  who,  by  reason  of  such  directorship  or
officership, is involved in any action, suit or proceeding (other than an action
by or in the right of the  corporation)  may be indemnified  by the  corporation
against expenses (including attorneys' fees), judgments,  fines and amounts paid
in settlement  actually and reasonably incurred by him or her in connection with
such action, suit or proceeding if he or she acted in good faith and in a manner
he or she  reasonably  believed to be in or not opposed to the best interests of
the corporation,  and, with respect to any criminal action or proceeding, has no
reasonable cause to believe that his or her conduct was unlawful.  A director or
officer who, by reason of such  directorship or officership,  is involved in any
action or suit by or in the right of the  corporation  may be indemnified by the
corporation against expenses (including attorneys' fees) actually and reasonably
incurred  by him or her in  connection  with the defense or  settlement  of such
action  or suit if he or she  acted  in good  faith  and in a  manner  he or she
reasonably  believed  to be in or not  opposed  to  the  best  interests  of the
corporation, except that no indemnification may be made in respect of any claim,
issue or matter as to which he or she shall have been  adjudged  to be liable to
the  corporation  unless  and only to the  extent  that a court  of  appropriate
jurisdiction shall approve such indemnification.

      The Company's  Certificate of Incorporation  provides that, to the maximum
extent  permitted  under  the  DGCL,  a  director  of the  Company  shall not be
personally  liable to the  Company or to any of its  stockholders  for  monetary
damages  for breach of  fiduciary  duty as a director  of the  Company.  Section
102(b)(7) of the DGCL permits a  corporation  to include in its  certificate  of
incorporation a provision that eliminates or limits the personal  liability of a
director to the corporation or its  stockholders for monetary damages for breach
of  fiduciary  duty as a  director;  provided,  that  such  provision  shall not
eliminate  or limit  the  liability  of a  director  (i) for any  breach  of the
director's duty of loyalty to the corporation or its stockholders, (ii) for acts
or omissions  not in good faith or which  involve  intentional  misconduct  or a
knowing  violation of law,  (iii) under  Section 174 of the DGCL or (iv) for any
transaction from which the director derived in improper personal benefit.

Item 7. Exemption from Registration Claimed.

      Not applicable.

Item 8. Exhibits.

Exhibit No.        Description
-----------        -----------
5.1               Opinion of Kaye, Scholer,  Fierman,  Hays & Handler, LLP  with
                  respect to the legality of the securities being registered.  
                  (Filed herewith).

23.1              Consent of KPMG Peat Marwick LLP.  (Filed herewith).

23.2              Consent of Kaye, Scholer, Fierman, Hays & Handler, LLP.  
                  (Included in Exhibit 5).

24.               Power of Attorney. (Included  on  signature  pages  to    this
                  Registration Statement).

99.1              ImClone   Systems   Incorporated  1998   Non-Qualified   Stock
                  Option Plan.  (Incorporated by reference to  Exhibit 10.69  of
                  ImClone  Systems  Incorporated's   Quarterly   Report  on Form
                  10-Q for the fiscal quarter ended June 30, 1998).

99.2              ImClone  Systems  Incorporated  1998 Employee  Stock  Purchase
                  Plan.   (Incorporated  by  reference   to  Exhibit  10.68   of
                  ImClone Systems  Incorporated's  Quarterly Report on Form 10-Q
                  for the fiscal quarter ended June 30, 1998).


                                       4
<PAGE>

99.3              Option Agreement,  dated  as  of   September 1, 1998,  between
                  ImClone Systems Incorporated and Ron Martell. (Filed herewith)

Item 9. Undertakings.

      (a) The undersigned registrant hereby undertakes:

            (1) to file,  during any  period in which  offers or sales are being
      made, a post-effective amendment to this Registration Statement:

                  (i) to include any prospectus  required by Section 10(a)(3) of
            the Securities Act of 1933;

                  (ii) to reflect in the  prospectus any facts or events arising
            after the effective date of this Registration Statement (or the most
            recent post-effective  amendment thereof) which,  individually or in
            the aggregate, represent a fundamental change in the information set
            forth in this Registration Statement. Notwithstanding the foregoing,
            any  increase or decrease  in volume of  securities  offered (if the
            total dollar value of securities offered would not exceed that which
            was  registered)  and any deviation  from the low or high end of the
            estimated  maximum  offering  range may be  reflected in the form of
            prospectus filed with the Commission  pursuant to Rule 424(b) if, in
            the  aggregate,  the changes in volume and price  represent  no more
            than a 20% change in the maximum aggregate  offering price set forth
            in the  "Calculation  of  Registration  Fee" table in the  effective
            registration statement;

                  (iii) to include any material  information with respect to the
            plan of distribution not previously  disclosed in this  Registration
            Statement  or any  material  change  to  such  information  in  this
            Registration Statement;

provided,  however,  that paragraphs (a)(1)(i) and (a)(1)(ii) above do not apply
if the  registration  statement  is on Form  S-3,  Form  S-8 or Form F-3 and the
information  required  to be  included in a  post-effective  amendment  by those
paragraphs  is  contained  in periodic  reports  filed with or  furnished to the
Commission  by the  registrant  pursuant  to Section 13 or Section  15(d) of the
Securities  Exchange  Act of 1934  that are  incorporated  by  reference  in the
registration statement;

            (2) that,  for the purpose of  determining  any liability  under the
      Securities Act of 1933, each such post-effective amendment shall be deemed
      a new registration  statement  relating to the securities offered therein,
      and the offering of such securities at that time shall be deemed to be the
      initial bona fide offering thereof; and

            (3)  to  remove  from  registration  by  means  of a  post-effective
      amendment any of the securities  being  registered  which remain unsold at
      the termination of the offering.

      (b) The undersigned  registrant  hereby  undertakes  that, for purposes of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Securities  Exchange  Act of 1934  (and,  where  applicable,  each  filing of an
employee  benefit  plan's  annual  report  pursuant  to  Section  15(d)  of  the
Securities  Exchange  Act of 1934)  that is  incorporated  by  reference  in the
registration  statement  shall  be  deemed  to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

      (c)  Insofar  as  indemnification   for  liabilities   arising  under  the
Securities Act of 1933 may be permitted to directors,  officers and  controlling
persons of the registrant  pursuant to the foregoing  provisions,  or otherwise,
the  registrant  has been  advised  that in the  opinion of the  Securities  and
Exchange  Commission 


                                       5
<PAGE>

such  indemnification  is against  public policy as expressed in the Act and is,
therefore,  unenforceable. In the event that a claim for indemnification against
such liabilities  (other than the payment by the registrant of expenses incurred
or paid by a director,  officer or  controlling  person of the registrant in the
successful  defense of any  action,  suit or  proceeding)  is  asserted  by such
director,  officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.


                                       6
<PAGE>

                                   SIGNATURES

      Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing  on Form S-8 and has  duly  caused  this  Registration
Statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized,  in the  City of New  York,  State of New  York,  on the 30th day of
September 1998.

                                      IMCLONE SYSTEMS INCORPORATED

                                      By: /S/ Samuel D. Waksal
                                         -----------------------------------
                                         Samuel D. Waksal
                                         President and Chief Executive Officer

      Pursuant  to  the  requirements  of  the  Securities  Act  of  1933,  this
Registration  Statement  has been signed below by the  following  persons in the
capacities and on the dates indicated.  Each person whose  individual  signature
appears below hereby authorizes  Samuel D. Waksal,  Harlan W. Waksal and John B.
Landes, or any of them, to execute in the name and on behalf of each such person
and to file any amendment to this Registration Statement, and appoints Samuel D.
Waksal, Harlan W. Waksal and John B. Landes, or any of them, as attorney-in-fact
to sign on his behalf  individually  and in each capacity  stated below,  and to
file  any  amendments  to this  Registration  Statement,  including  any and all
post-effective amendments.

       Signature                      Title                          Date
       ---------                      -----                          ----

/S/  Robert F. Goldhammer     Chairman of the Board           September 30, 1998
-------------------------     and Director
Robert F. Goldhammer

/S/  Samuel D. Waksal         President, Chief Executive      September 30, 1998
---------------------         Officer and Director
Samuel D. Waksal              (Principal Executive Officer)
                              
/S/  Harlan W. Waksal         Executive Vice President,       September 30, 1998
---------------------         Chief Operating Officer
Harlan W. Waksal              and Director

/S/  Carl Goldfischer         Vice President of Finance       September 30, 1998
---------------------         and Chief Financial Officer
Carl Goldfischer              (Principal Financial and 
                              Accounting Officer)

/S/  Jean Carvais             Director                        September 30, 1998
-----------------------
Jean Carvais

/S/  Vincent T. DeVita, Jr.   Director                        September 30, 1998
---------------------------
Vincent T. DeVita, Jr.

/S/  Paul B. Kopperl          Director                        September 30, 1998
-----------------------
Paul B. Kopperl

/S/  William R. Miller        Director                        September 30, 1998
-----------------------
William R. Miller

/S/  David M. Kies            Director                        September 30, 1998
-----------------------
David M. Kies

/S/  Richard Barth            Director                        September 30, 1998
-----------------------
Richard Barth

/S/  John Mendelsohn          Director                        September 30, 1998
-----------------------
John Mendelsohn


                                      S-1
<PAGE>

                                  EXHIBIT INDEX

Exhibit
No.              Description
-------          ------------
5.1              Opinion of Messrs. Kaye, Scholer, Fierman, Hays & Handler, LLP.
                 (Filed herewith).

23.1             Consent of KPMG Peat Marwick LLP.  (Filed herewith).

23.2             Consent of Kaye, Scholer, Fierman, Hays & Handler, LLP. 
                 (Included in Exhibit 5).

24.              Power of Attorney.  (Included on signature pages to this 
                 Registration Statement).

99.1            ImClone Systems  Incorporated  1998  Non-Qualified  Stock Option
                Plan.  (Incorporated by reference to Exhibit 10.69 of ImClone 
                Systems  Incorporated's  Quarterly  Report on Form 10-Q for
                the fiscal quarter ended June 30, 1998).

99.2            ImClone  Systems  Incorporated  1998 Employee  Stock  Purchase 
                Plan.  (Incorporated  by reference to  Exhibit 10.68 of ImClone 
                Systems  Incorporated's  Quarterly Report on Form 10-Q for
                the quarterly period ended June 30, 1998).

99.3            Option Agreement,  dated as of September 1, 1998,  between 
                ImClone Systems  Incorporated and Ron Martell. (Filed herewith)
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 23260}]
{"company-data": {"conformed-name": "IMCLONE SYSTEMS INC/DE", "cik": "0000765258", "assigned-sic": "2836", "irs-number": "042834797", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-64827", "film-number": "98718421"}, "business-address": {"street1": "180 VARICK ST", "city": "NEW YORK", "state": "NY", "zip": "10014", "phone": "2126451405"}, "mail-address": {"street1": "180 VARICK ST", "city": "NEW YORK", "state": "NY", "zip": "10014"}}
As filed with the Securities and Exchange Commission on September 30, 1998

                                                   Registration No.
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                               ------------------

                                    FORM S-8

             REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                          IMCLONE SYSTEMS INCORPORATED
             (Exact name of registrant as specified in its charter)

             Delaware                                            04-2834797
  (State or other jurisdiction of                             (I.R.S. Employer
  incorporation or organization)                             Identification No.)

             180 Varick Street
            New York, New York                                      10014
 (Address of Principal Executive Offices)                        (Zip Code)

  ImClone Systems Incorporated 1998 Non-Qualified Stock Option Plan, As Amended
         ImClone Systems Incorporated 1998 Employee Stock Purchase Plan
                Option to Purchase 60,000 Shares of Common Stock
                            (Full title of the plan)

                               ------------------

                                 John B. Landes
            Vice President, Business Development and General Counsel
                          ImClone Systems Incorporated
                                180 Varick Street
                            New York, New York 10014
                     (Name and address of agent for service)

                                 (212) 645-1405
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                           Lawrence A. Darby III, Esq.
                   Kaye, Scholer, Fierman, Hays & Handler, LLP
                                 425 Park Avenue
                          New York, New York 10022-3598

                         CALCULATION OF REGISTRATION FEE

================================================================================
Title of       Amount          Proposed maximum Proposed maximum    Amount of
securities to  to be           offering price   aggregate           registration
be registered  registered(1)   per share(2)     offering price(2)   fee
--------------------------------------------------------------------------------
Common Stock, 
$.001 par      
value .......    637,000          $11.44          $7,287,280         $2,150
                 363,000            9.625          3,493,875          1,031
                 500,000            9.625          4,812,500          1,420
                  60,000           10.125            607,500            180
--------------------------------------------------------------------------------
  Totals ....  1,560,000                         $16,201,155         $4,781
================================================================================

----------
(1)   Excludes such additional indeterminate number of shares as may be issuable
      pursuant to the anti-dilution  provisions of the Plans (as defined) or the
      Martell Option (as defined). This total represents (i) 1,000,000 shares of
      Common  Stock and 500,000  shares of Common  Stock  reserved  for issuance
      pursuant  to options  granted or which may be  granted  under the  ImClone
      Systems Incorporated 1998 Non-Qualified Stock Option Plan, As Amended, and
      the ImClone  Systems  Incorporated  1998  Employee  Stock  Purchase  Plan,
      respectively  (together,  the  "Plans")  and (ii) 60,000  shares of Common
      Stock reserved for  issuance to the Company's,  Vice President, Marketing,
      pursuant to a certain Option Agreement dated as of September 1, 1998.

(2)   Estimated  solely for the purposes of calculating  the  registration  fee.
      Pursuant to Rule 457(c) and Rule 457(h) under the  Securities Act of 1933,
      as amended, the proposed maximum offering price per share and the proposed
      maximum aggregate offering price of shares subject to outstanding  options
      have been  determined on the basis of the average  exercise  prices of the
      outstanding  options and shares not subject to  outstanding  options  have
      been  determined  based on the  average  of the high and low prices of the
      Common Stock on September  29,  1998,  as reported by the NASDAQ  National
      Market.
SECTION 10(a) PROSPECTUS

      The  documents  containing  the  information  specified  in Part I of this
Registration  Statement on Form S-8 will be sent or given to participants in the
Plans as  specified  by Rule  428(b)(i)  under the  Securities  Act of 1933,  as
amended.  Such documents are not required to be, and are not being, filed by the
Company  with the  Securities  and Exchange  Commission,  either as part of this
Registration  Statement or as prospectuses or prospectus supplements pursuant to
Rule 424 under the Securities Act of 1933, as amended. Such documents,  together
with the documents  incorporated by reference  herein pursuant to Item 3 of Part
II of this  Registration  Statement on Form S-8,  constitute  a prospectus  that
meets the  requirements  of  Section  10(a) of the  Securities  Act of 1933,  as
amended.

                                       2
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

      The  following  documents  which  have  heretofore  been  filed by ImClone
Systems  Incorporated,   a  Delaware  corporation  (the  "Company"),   with  the
Securities and Exchange Commission (the "Commission") pursuant to the Securities
Exchange Act of 1934,  as amended (the  "Exchange  Act"),  are  incorporated  by
reference herein and shall be deemed to be a part hereof:

1.   The Company's Annual Report on Form 10-K for the fiscal year ended December
     31, 1997.

2.   The Company's  Quarterly Reports on Form 10-Q for the fiscal quarters ended
     March 31, 1998 and June 30, 1998.

3.   The  Company's  Current  Report on Form 8-K filed  with the  Commission  on
     February 10, 1998.

4.   The description of the Company's  Common Stock,  par value $.001 per share,
     contained  in its  Registration  Statement  on Form  8-A  filed  under  the
     Exchange  Act,  including  any amendment or report filed for the purpose of
     updating such description.

      All other documents  filed by the Company with the Commission  pursuant to
Sections  13(a),  13(c), 14 and 15(d) of the Exchange Act subsequent to the date
of this  Registration  Statement  and prior to the  filing  of a  post-effective
amendment to this  Registration  Statement  which  indicates that all securities
offered  have been sold or which  de-registers  all  securities  then  remaining
unsold,  shall be deemed to be  incorporated  by reference in this  Registration
Statement  and to be a part  hereof  from the date of filing  of such  documents
(such documents,  and the documents enumerated above, being hereinafter referred
to collectively as the "Incorporated Documents").

      Any statement contained in an Incorporated  Document shall be deemed to be
modified or superseded for purposes of this Registration Statement to the extent
that  a  statement   contained  therein  or  in  any  other  subsequently  filed
Incorporated Document modifies or supersedes such statement. Any such statements
so  modified  or  superseded  shall  not be  deemed,  except as so  modified  or
superseded, to constitute a part of this Registration Statement.

Item 4. Description of Securities.

      Not applicable.

Item 5. Interest of Named Experts and Counsel.

      Not applicable.

Item 6. Indemnification of Directors and Officers.

      The Company's Certificate of Incorporation and Bylaws set forth the extent
to which  officers and directors of the Company may be  indemnified  against any
liabilities which they may incur. The general effect of such provisions is that,
on  the  terms  and  conditions  set  forth  in  the  Company's  Certificate  of
Incorporation  and Bylaws,  any person made a party or  threatened  to be made a
party to an action,  suit or  proceeding by reason of the fact that he or she is
or was a director or officer of the Company, or is or was serving as a director,
officer,  employee or agent of another  corporation  or other  enterprise at the
request of the Company,  shall be  indemnified by the Company  against  expenses
(including  attorneys'  fees,  judgments,  fines and amounts paid in settlement)
reasonably  incurred or suffered by him or her in  connection  with such action,
suit or proceeding,  to the full extent permitted under the laws of the State of
Delaware;  provided,  however, that, subject to certain limited exceptions,  the
Company shall  indemnify any such person 

                                       3
seeking indemnification in connection with a proceeding initiated by such person
only if such proceeding was authorized by the Board of Directors of the Company.
The Company's  Certificate of Incorporation  gives the Board of Directors of the
Company the  authority to extend such  indemnification  to  employees  and other
agents of the Company as well.

      The general effect of the indemnification  provisions contained in Section
145 of the General  Corporation  Law of the State of Delaware (the "DGCL") is as
follows:  A  director  or  officer  who,  by  reason  of  such  directorship  or
officership, is involved in any action, suit or proceeding (other than an action
by or in the right of the  corporation)  may be indemnified  by the  corporation
against expenses (including attorneys' fees), judgments,  fines and amounts paid
in settlement  actually and reasonably incurred by him or her in connection with
such action, suit or proceeding if he or she acted in good faith and in a manner
he or she  reasonably  believed to be in or not opposed to the best interests of
the corporation,  and, with respect to any criminal action or proceeding, has no
reasonable cause to believe that his or her conduct was unlawful.  A director or
officer who, by reason of such  directorship or officership,  is involved in any
action or suit by or in the right of the  corporation  may be indemnified by the
corporation against expenses (including attorneys' fees) actually and reasonably
incurred  by him or her in  connection  with the defense or  settlement  of such
action  or suit if he or she  acted  in good  faith  and in a  manner  he or she
reasonably  believed  to be in or not  opposed  to  the  best  interests  of the
corporation, except that no indemnification may be made in respect of any claim,
issue or matter as to which he or she shall have been  adjudged  to be liable to
the  corporation  unless  and only to the  extent  that a court  of  appropriate
jurisdiction shall approve such indemnification.

      The Company's  Certificate of Incorporation  provides that, to the maximum
extent  permitted  under  the  DGCL,  a  director  of the  Company  shall not be
personally  liable to the  Company or to any of its  stockholders  for  monetary
damages  for breach of  fiduciary  duty as a director  of the  Company.  Section
102(b)(7) of the DGCL permits a  corporation  to include in its  certificate  of
incorporation a provision that eliminates or limits the personal  liability of a
director to the corporation or its  stockholders for monetary damages for breach
of  fiduciary  duty as a  director;  provided,  that  such  provision  shall not
eliminate  or limit  the  liability  of a  director  (i) for any  breach  of the
director's duty of loyalty to the corporation or its stockholders, (ii) for acts
or omissions  not in good faith or which  involve  intentional  misconduct  or a
knowing  violation of law,  (iii) under  Section 174 of the DGCL or (iv) for any
transaction from which the director derived in improper personal benefit.

Item 7. Exemption from Registration Claimed.

      Not applicable.

Item 8. Exhibits.

Exhibit No.        Description
-----------        -----------
5.1               Opinion of Kaye, Scholer,  Fierman,  Hays & Handler, LLP  with
                  respect to the legality of the securities being registered.  
                  (Filed herewith).

23.1              Consent of KPMG Peat Marwick LLP.  (Filed herewith).

23.2              Consent of Kaye, Scholer, Fierman, Hays & Handler, LLP.  
                  (Included in Exhibit 5).

24.               Power of Attorney. (Included  on  signature  pages  to    this
                  Registration Statement).

99.1              ImClone   Systems   Incorporated  1998   Non-Qualified   Stock
                  Option Plan.  (Incorporated by reference to  Exhibit 10.69  of
                  ImClone  Systems  Incorporated's   Quarterly   Report  on Form
                  10-Q for the fiscal quarter ended June 30, 1998).

99.2              ImClone  Systems  Incorporated  1998 Employee  Stock  Purchase
                  Plan.   (Incorporated  by  reference   to  Exhibit  10.68   of
                  ImClone Systems  Incorporated's  Quarterly Report on Form 10-Q
                  for the fiscal quarter ended June 30, 1998).

                                       4
99.3              Option Agreement,  dated  as  of   September 1, 1998,  between
                  ImClone Systems Incorporated and Ron Martell. (Filed herewith)

Item 9. Undertakings.

      (a) The undersigned registrant hereby undertakes:

            (1) to file,  during any  period in which  offers or sales are being
      made, a post-effective amendment to this Registration Statement:

                  (i) to include any prospectus  required by Section 10(a)(3) of
            the Securities Act of 1933;

                  (ii) to reflect in the  prospectus any facts or events arising
            after the effective date of this Registration Statement (or the most
            recent post-effective  amendment thereof) which,  individually or in
            the aggregate, represent a fundamental change in the information set
            forth in this Registration Statement. Notwithstanding the foregoing,
            any  increase or decrease  in volume of  securities  offered (if the
            total dollar value of securities offered would not exceed that which
            was  registered)  and any deviation  from the low or high end of the
            estimated  maximum  offering  range may be  reflected in the form of
            prospectus filed with the Commission  pursuant to Rule 424(b) if, in
            the  aggregate,  the changes in volume and price  represent  no more
            than a 20% change in the maximum aggregate  offering price set forth
            in the  "Calculation  of  Registration  Fee" table in the  effective
            registration statement;

                  (iii) to include any material  information with respect to the
            plan of distribution not previously  disclosed in this  Registration
            Statement  or any  material  change  to  such  information  in  this
            Registration Statement;

provided,  however,  that paragraphs (a)(1)(i) and (a)(1)(ii) above do not apply
if the  registration  statement  is on Form  S-3,  Form  S-8 or Form F-3 and the
information  required  to be  included in a  post-effective  amendment  by those
paragraphs  is  contained  in periodic  reports  filed with or  furnished to the
Commission  by the  registrant  pursuant  to Section 13 or Section  15(d) of the
Securities  Exchange  Act of 1934  that are  incorporated  by  reference  in the
registration statement;

            (2) that,  for the purpose of  determining  any liability  under the
      Securities Act of 1933, each such post-effective amendment shall be deemed
      a new registration  statement  relating to the securities offered therein,
      and the offering of such securities at that time shall be deemed to be the
      initial bona fide offering thereof; and

            (3)  to  remove  from  registration  by  means  of a  post-effective
      amendment any of the securities  being  registered  which remain unsold at
      the termination of the offering.

      (b) The undersigned  registrant  hereby  undertakes  that, for purposes of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Securities  Exchange  Act of 1934  (and,  where  applicable,  each  filing of an
employee  benefit  plan's  annual  report  pursuant  to  Section  15(d)  of  the
Securities  Exchange  Act of 1934)  that is  incorporated  by  reference  in the
registration  statement  shall  be  deemed  to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

      (c)  Insofar  as  indemnification   for  liabilities   arising  under  the
Securities Act of 1933 may be permitted to directors,  officers and  controlling
persons of the registrant  pursuant to the foregoing  provisions,  or otherwise,
the  registrant  has been  advised  that in the  opinion of the  Securities  and
Exchange  Commission 

                                       5
such  indemnification  is against  public policy as expressed in the Act and is,
therefore,  unenforceable. In the event that a claim for indemnification against
such liabilities  (other than the payment by the registrant of expenses incurred
or paid by a director,  officer or  controlling  person of the registrant in the
successful  defense of any  action,  suit or  proceeding)  is  asserted  by such
director,  officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.

                                       6
SIGNATURES

      Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing  on Form S-8 and has  duly  caused  this  Registration
Statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized,  in the  City of New  York,  State of New  York,  on the 30th day of
September 1998.

                                      IMCLONE SYSTEMS INCORPORATED

                                      By: /S/ Samuel D. Waksal
                                         -----------------------------------
                                         Samuel D. Waksal
                                         President and Chief Executive Officer

      Pursuant  to  the  requirements  of  the  Securities  Act  of  1933,  this
Registration  Statement  has been signed below by the  following  persons in the
capacities and on the dates indicated.  Each person whose  individual  signature
appears below hereby authorizes  Samuel D. Waksal,  Harlan W. Waksal and John B.
Landes, or any of them, to execute in the name and on behalf of each such person
and to file any amendment to this Registration Statement, and appoints Samuel D.
Waksal, Harlan W. Waksal and John B. Landes, or any of them, as attorney-in-fact
to sign on his behalf  individually  and in each capacity  stated below,  and to
file  any  amendments  to this  Registration  Statement,  including  any and all
post-effective amendments.

       Signature                      Title                          Date
       ---------                      -----                          ----

/S/  Robert F. Goldhammer     Chairman of the Board           September 30, 1998
-------------------------     and Director
Robert F. Goldhammer

/S/  Samuel D. Waksal         President, Chief Executive      September 30, 1998
---------------------         Officer and Director
Samuel D. Waksal              (Principal Executive Officer)
                              
/S/  Harlan W. Waksal         Executive Vice President,       September 30, 1998
---------------------         Chief Operating Officer
Harlan W. Waksal              and Director

/S/  Carl Goldfischer         Vice President of Finance       September 30, 1998
---------------------         and Chief Financial Officer
Carl Goldfischer              (Principal Financial and 
                              Accounting Officer)

/S/  Jean Carvais             Director                        September 30, 1998
-----------------------
Jean Carvais

/S/  Vincent T. DeVita, Jr.   Director                        September 30, 1998
---------------------------
Vincent T. DeVita, Jr.

/S/  Paul B. Kopperl          Director                        September 30, 1998
-----------------------
Paul B. Kopperl

/S/  William R. Miller        Director                        September 30, 1998
-----------------------
William R. Miller

/S/  David M. Kies            Director                        September 30, 1998
-----------------------
David M. Kies

/S/  Richard Barth            Director                        September 30, 1998
-----------------------
Richard Barth

/S/  John Mendelsohn          Director                        September 30, 1998
-----------------------
John Mendelsohn

                                      S-1
EXHIBIT INDEX

Exhibit
No.              Description
-------          ------------
5.1              Opinion of Messrs. Kaye, Scholer, Fierman, Hays & Handler, LLP.
                 (Filed herewith).

23.1             Consent of KPMG Peat Marwick LLP.  (Filed herewith).

23.2             Consent of Kaye, Scholer, Fierman, Hays & Handler, LLP. 
                 (Included in Exhibit 5).

24.              Power of Attorney.  (Included on signature pages to this 
                 Registration Statement).

99.1            ImClone Systems  Incorporated  1998  Non-Qualified  Stock Option
                Plan.  (Incorporated by reference to Exhibit 10.69 of ImClone 
                Systems  Incorporated's  Quarterly  Report on Form 10-Q for
                the fiscal quarter ended June 30, 1998).

99.2            ImClone  Systems  Incorporated  1998 Employee  Stock  Purchase 
                Plan.  (Incorporated  by reference to  Exhibit 10.68 of ImClone 
                Systems  Incorporated's  Quarterly Report on Form 10-Q for
                the quarterly period ended June 30, 1998).

99.3            Option Agreement,  dated as of September 1, 1998,  between 
                ImClone Systems  Incorporated and Ron Martell. (Filed herewith)