As filed with the Securities and Exchange Commission on August 9, 2002
                                                      Registration No. 333-64076
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                 POST-EFFECTIVE
                                 AMENDMENT NO. 1
                                       TO
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                             ----------------------

                                MONSANTO COMPANY
             (Exact name of registrant as specified in its charter)

              DELAWARE                                      43-1878297
  (State or other jurisdiction of                        (I.R.S. Employer
   incorporation or organization)                      Identification Number)


                          800 NORTH LINDBERGH BOULEVARD
                            ST. LOUIS, MISSOURI 63167
              (Address of registrant's principal executive offices)

            MONSANTO COMPANY ERISA PARITY SAVINGS AND INVESTMENT PLAN
                              (Full title of plan)

                                CHARLES W. BURSON
             EXECUTIVE VICE PRESIDENT, SECRETARY AND GENERAL COUNSEL
                                MONSANTO COMPANY
                          800 NORTH LINDBERGH BOULEVARD
                            ST. LOUIS, MISSOURI 63167
                                 (314) 694-1000
            (Name, address and telephone number of agent for service)




                                CALCULATION OF REGISTRATION FEE
- -------------------------------------------  ----------------------------  -----------------
              TITLE OF                             PROPOSED MAXIMUM           AMOUNT OF
     SECURITIES TO BE REGISTERED             AGGREGATE OFFERING PRICE (1)  REGISTRATION FEE
- -------------------------------------------  ----------------------------  -----------------

                                                                      
Savings and Investment Plan Obligations (2)         $24,000,000             $6,000.00 (3)
- -------------------------------------------  ----------------------------  -----------------


(1)  Estimated solely for the purpose of calculating the registration fee, which
     is calculated in accordance Rule 457(o).

(2)  The Savings and Investment Plan  Obligations  are unsecured  obligations of
     Monsanto Company to pay deferred  compensation in accordance with the terms
     of  the  Monsanto   Company  ERISA  Parity  Savings  and  Investment  Plan.

(3)  Fee previously paid.

================================================================================

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

     The following  documents filed by Monsanto Company (the  "Registrant") with
the Securities and Exchange Commission ("SEC") under SEC File Number 1-16167 are
hereby incorporated by reference and made a part of this Registration Statement:

     (a) Registrant's Annual Report on Form 10-K for the year ended December 31,
2001;

     (b) Registrant's  Quarterly Report on Form 10-Q for the quarter ended March
31, 2002;

     (c) Registrant's Current Report on Form 8-K filed with the SEC on March 12,
2002;

     (d) Item 5 and Exhibits  99.1,  99.2 and 99.3 of Item 7(c) of  Registrant's
Current Report on Form 8-K filed with the SEC on July 30, 2002; and

     (e)  Registrant's  Definitive  Proxy  Statement for its 2002 Annual Meeting
filed with the SEC on March 25, 2002;

     All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14
and  15(d)  of the  Securities  Exchange  Act of 1934  (except  for  information
furnished  under Item 9 on Form 8-K,  or under any other Item on Form 8-K or any
other form that permits the furnishing of information  pursuant to Regulation FD
(or any  successor  thereto)  without being deemed to be "filed" for purposes of
the  Securities  Exchange  Act of  1934)  after  the  date of this  Registration
Statement  and  prior  to the  filing  of a  post-effective  amendment  to  this
Registration  Statement  which  indicates that all Savings and  Investment  Plan
Obligations  (the  "Obligations")   offered  hereby  have  been  sold  or  which
deregisters  the  Obligations  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
listed above, being hereinafter  referred to as "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  herein or in any  other  subsequently  filed  Incorporated
Document  modifies or supersedes such statement.  Any such statement 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.

     The  Obligations  are  unsecured  obligations  of  the  Registrant  to  pay
employees'  compensation which has been deferred under the terms of the Monsanto
Company ERISA Parity Savings and Investment  Plan (the "Plan").  The Obligations
rank equally with all other  unsecured and  unsubordinated  indebtedness  of the
Registrant.

     Compensation deferred ("Employee Deferrals") by a participating employee (a
"Participant"),  together with any employer contribution ("Employer Match"), are
held  in  the  general  funds  of the  Registrant.  The  Registrant  establishes
individual  bookkeeping  accounts for each Participant.  Employee  Deferrals are
allocated to a Participant's accounts in accordance with investment alternatives
selected by the Participant and the terms of the Plan.  Investment  alternatives
include (i) two stock  accounts  (one for Employee  Deferrals  and the other for
Employer Match) treated as though invested in the common stock of the Registrant
("Stock  Accounts")  and (ii)  accounts  treated as though  invested  in certain
pre-mixed  diversified  portfolios or managed  investment funds specified in the
Plan. Employer Matches are automatically treated as invested in one of the Stock
Accounts, subject to certain exceptions. Employee Deferrals and Employer Matches
treated as invested in the Stock Accounts accrue dividend  equivalents  that are
treated as reinvested.  A  Participant's  Stock Accounts  reflect,  in all other
respects,  share  ownership for events such as a stock split,  but a Participant
has no voting rights.

     Neither  the   establishment   of  individual   bookkeeping   accounts  for
Participants  nor the  allocation or reservation by the Registrant of funds with
respect  to such  accounts  shall be  deemed  to have  created  a trust,  and no
Participant   shall  have  an  ownership   interest  in  any  such  account.   A
Participant's   rights  to  any  amounts   credited  to  his  accounts  are  not
transferable or assignable.

     Obligations  are  not  subject  to  redemption,  in  whole  or in  part  by
Participants, except upon termination of employment or death as specified in the
Plan.  The  Registrant  reserves  the right to  amend,  merge,  consolidate,  or
terminate  the Plan at any time,  except  that such action  shall not  adversely
affect the amount that any Participant is entitled to receive.


ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

     Not applicable.


ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

     Section 145 of the General Corporation Law of the State of Delaware permits
indemnification  of directors,  officers,  employees and agents of  corporations
under certain conditions and subject to certain  limitations.  Section 60 of the
Registrant's By-Laws requires  indemnification of any person made a party to any
proceeding by reason of the fact that the person is or was a director or officer
of the  Registrant,  or serving at the request of the  Registrant as a director,
officer or fiduciary of another  enterprise,  including  employee benefit plans;
and  permits  indemnification  of any person made a party to any  proceeding  by
reason  of the  fact  that  the  person  is or was an  employee  or agent of the
Registrant,  or was serving at the request of the  Registrant  as an employee or
agent of another  enterprise,  including  employee  benefit  plans.  The By-Laws
provide  for  certain  conditions  to such  indemnification.  Article  IX of the
Registrant's  Restated Certificate of Incorporation  eliminates the liability of
directors  of  the  Registrant  under  certain  circumstances  for  breaches  of
fiduciary duty to the Registrant and its shareholders.

     The  Registrant  maintains  directors'  and officers'  liability  insurance
coverage.


ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

     Not Applicable


ITEM 8.  EXHIBITS.



EXHIBIT NUMBER                       DESCRIPTION
- --------------                       -----------

                
        4.1        Monsanto Company ERISA Parity Savings and Investment Plan

        5.1        Opinion of Sonnenschein Nath & Rosenthal*

       23.1        Consent of Deloitte & Touche LLP

       23.2        Consent of Sonnenschein Nath & Rosenthal (reference is made to Exhibit 5.1 hereto)*

       24.1        Power of Attorney*

- ---------------
* Previously filed as an exhibit to this Registration Statement.



ITEM 9.  UNDERTAKINGS.

(a)  The Registrant hereby undertakes:

     (1) To file,  during any period in which  offers or sales are being made of
     the  securities  registered  hereby,  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 (the "Securities Act");

          (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; and

          (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 the  undertakings  set  forth in  paragraphs
          (a)(1)(i)  and  (a)(1)(ii)  above  do not  apply  if  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 SEC by the  Registrant  pursuant to Section 13 or Section 15(d) of
          the  Securities  Exchange  Act of 1934 (the  "Exchange  Act") that are
          incorporated by reference in this Registration Statement.

          (2) That,  for the  purpose of  determining  any  liability  under the
          Securities Act, each such post-effective  amendment 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.

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

(b) The Registrant  hereby  undertakes  that,  for purposes of  determining  any
liability  under the  Securities  Act,  each filing of the  Registrant's  annual
report  pursuant to Section  13(a) or Section 15(d) of the Exchange Act and each
filing of the Plan's annual report pursuant to Section 15(d) of the Exchange Act
that is incorporated by reference in this Registration Statement shall be deemed
to be a new registration  statement  relating to the securities  offered herein,
and the  offering  of such  securities  at that  time  shall be deemed to be the
initial bona fide offering thereof.

     Insofar as indemnification for liabilities arising under the Securities Act
may  be  permitted  to  directors,  officers  and  controlling  persons  of  the
Registrant  pursuant to Item 6 above,  or  otherwise,  the  Registrant  has been
advised  that in the opinion of the  Securities  and  Exchange  Commission  such
indemnification is against public policy as expressed in the Securities 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  Securities  Act and will be  governed by the final
adjudication of such issue.



                                   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  Post-Effective
Amendment  to the  Registration  Statement  to be  signed  on its  behalf by the
undersigned,  thereunto  duly  authorized,  in the City of St.  Louis,  State of
Missouri, on August 9, 2002.


                                 MONSANTO COMPANY


                                 By: /s/ Richard B. Clark
                                     --------------------------------------
                                     Name:    Richard B. Clark
                                     Title:   Vice President and Controller



Pursuant to the  requirements of the Securities Act of 1933,  this  Registration
Statement has been signed by the following  persons in the capacities and on the
dates indicated.

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


                *            Chairman and Director              August 9, 2002
- -------------------------
Frank V. Atlee III


                *            President and Chief Executive      August 9, 2002
- -------------------------    Officer (Principal
Hendrik A. Verfaillie        Executive Officer)


                 *           Executive Vice President           August 9, 2002
- -------------------------    and Chief Financial Officer
Terrell K. Crews             (Principal Financial Officer)


/s/ Richard B. Clark         Vice President and Controller      August 9, 2002
- -------------------------    (Principal Accounting Officer)
Richard B. Clark

                 *           Director                           August 9, 2002
- -------------------------
Christopher J. Coughlin


                 *           Director                           August 9, 2002
- -------------------------
Michael Kantor


                 *           Director                           August 9, 2002
- -------------------------
Gwendolyn S. King


                             Director
- -------------------------
Sharon R. Long


/s/ Philip Needleman         Director                           August 9, 2002
- -------------------------
Philip Needleman


                *            Director                           August 9, 2002
- -------------------------
C. Steven McMillan


                 *           Director                           August 9, 2002
- -------------------------
William U. Parfet


                 *           Director                           August 9, 2002
- -------------------------
John S. Reed


* Charles W.  Burson,  by signing his name  hereto,  does sign this  document on
behalf of the above  noted  individuals,  pursuant  to powers of  attorney  duly
executed by such  individuals  which have been previously filed as an Exhibit to
this Registration Statement.


                                       /s/ Charles W. Burson
                                       ---------------------------
                                       By:  Charles W. Burson
                                            Attorney-in-Fact





                                  EXHIBIT INDEX

EXHIBIT NUMBER                         DESCRIPTION
- --------------                         -----------

                  
        4.1          Monsanto Company ERISA Parity Savings and Investment Plan

        5.1          Opinion of Sonnenschein Nath & Rosenthal*

       23.1          Consent of Deloitte & Touche LLP

       23.2          Consent of Sonnenschein Nath & Rosenthal (reference is made to Exhibit 5.1 hereto)*

       24.1          Power of Attorney*

- ---------------
* Previously filed as an exhibit to this Registration Statement.