As filed with the Securities and Exchange Commission on September 18, 2003
                              Registration No. 33-


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                    FORM S-8


                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933


                              IONICS, INCORPORATED
             (Exact name of registrant as specified in its charter)


      Massachusetts                                     04-2068530
 (State of incorporation)                  (IRS employer identification number)



                                 65 Grove Street
                       Watertown, Massachusetts 02472-2882
              (Address and zip code of principal executive offices)


                 INDUCEMENT NON-QUALIFIED STOCK OPTION AGREEMENT
                            (Full title of the Plan)


                               Stephen Korn, Esq.
                        Vice President & General Counsel
                              Ionics, Incorporated
                                 65 Grove Street
                       Watertown, Massachusetts 02472-2882
                     (Name and address of agent for service)


                                  617-926-2500
          (Telephone number, including area code, of agent for service)




                                    Page -1-
<PAGE>

<TABLE>
<CAPTION>


                         CALCULATION OF REGISTRATION FEE

                                                                   Proposed           Proposed
                                                                   Maximum            Maximum
                                            Amount to be       Offering Price        Aggregate            Amount of
 Title of Securities to be Registered      Registered (1)         Per Share       Offering Price      Registration Fee
 ------------------------------------      --------------         ---------       --------------      ----------------
<S>                                            <C>                 <C>              <C>                    <C>
Common Stock (Par Value $1.00 Per
Share)                                         200,000             $22.00           $4,400,000             $355.96

Total                                          200,000             $22.00           $4,400,000             $355.96
</TABLE>


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

(1)      Pursuant to Rule 416(a) under the Securities Act of 1933, this
         Registration Statement shall also cover any additional shares of Common
         Stock which become issuable upon exercise of options granted under the
         Inducement Non-Qualified Stock Option Agreement by reason of any stock
         dividend, stock split, recapitalization or other similar transaction.



                                    Page -2-
<PAGE>



                                     PART I


Item 1.    Plan Information

           The documents containing the information specified in this Item 1
           will be sent or given to the Vice President, Strategy and Operations
           of the Registrant, to whom the Inducement Non-Qualified Stock Option
           Agreement was granted on August 28, 2003, as specified by Rule 428(b)
           (1). In accordance with the rules and regulations of the Securities
           and Exchange Commission (the "Commission") and the instructions to
           Form S-8, such documents are not being filed with the Commission
           either as part of this Registration Statement or as prospectuses or
           prospectus supplements pursuant to Rule 424.

Item 2.    Registrant Information and Employee Plan Annual Information

           The documents containing the information specified in this Item 2
           will be sent or given to the Vice President, Strategy and Operations
           as specified by Rule 428(b) (1). In accordance with the rules and
           regulations of the Commission and the instructions to Form S-8, such
           documents are not being filed with the Commission either as part of
           this Registration Statement or as prospectuses or prospectus
           supplements pursuant to Rule 424.


                                     PART II


               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.    Incorporation of Documents by Reference

           The following documents filed with the Commission are incorporated by
           reference in this Prospectus:

          (a)  The Annual  Report of the  Registrant on Form 10-K for the fiscal
               year ended December 31, 2002,  filed with the Commission on March
               31, 2003  pursuant to the  Securities  Exchange  Act of 1934,  as
               amended,  which  contains  audited  financial  statements  of the
               Registrant  for the  fiscal  year ended  December  31,  2002,  as
               amended  by Form  10-K/A  filed with the  Commission  on April 1,
               2003.

           (b)(1) The Quarterly Report of the Registrant on Form 10-Q for the
                  fiscal quarter ended March 31, 2003, filed with the Commission
                  on May 15, 2003 pursuant to the Securities Exchange Act of
                  1934, as amended, which contains unaudited financial
                  statements of the Registrant for the fiscal quarter ended
                  March 31, 2003.

               (2) The Quarterly Report of the Registrant on Form 10-Q for the
                  fiscal quarter ended June 30, 2003, filed with the Commission
                  on August 13, 2003 pursuant to the Securities and Exchange Act
                  of 1934, as amended, which contains unaudited financial
                  statements of the Registrant for the fiscal quarter ended June
                  30, 2003.

          (c)  The section entitled  "Description of Registrant's  Securities to
               be  Registered"   contained  in  the  Registrant's   Registration
               Statement on Form 8-A, filed with the Commission on September 27,
               1990 pursuant to Section 12(g) of the Exchange Act.

               All  documents  subsequently  filed  with the  Commission  by the
               Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the
               Exchange Act, prior to the filing of a  post-effective  amendment
               which indicates that all securities offered herein have been sold
               or which deregisters all securities then remaining unsold,  shall


                                    Page -3-
<PAGE>

               be deemed to be  incorporated  by reference in this  Registration
               Statement  and to be a part  hereof  from the date of filing such
               documents.

Item 4.    Description of Securities
           -------------------------

           Not applicable.

Item 5.    Interest of Named Experts and Counsel
           -------------------------------------

           The validity of the shares of Common Stock offered hereby will be
           passed upon for the Registrant by Stephen Korn, Esq., Vice President
           and General Counsel of the Registrant. Mr. Korn is the beneficial
           owner of 128,814 shares of Common Stock, including 126,000 shares of
           Common Stock in the form of presently exercisable stock options and
           1,591 shares held in the Ionics Section 401(k) Stock Savings Plan
           (based on August 31, 2003 data).

Item 6.    Indemnification of Directors and Officers
           -----------------------------------------

           The Registrant is permitted by Massachusetts law and required by its
           By-laws to indemnify any director or officer or former director or
           officer against all expenses and liabilities reasonably incurred by
           him in connection with any legal action in which such person is
           involved by reason of his position with the Registrant unless he
           shall have been finally adjudicated in any action, suit or proceeding
           not to have acted in good faith in the reasonable belief that his
           action was in the best interests of the Registrant. Such
           indemnification shall include payment by the Registrant of expenses
           incurred in defending a civil or criminal action or proceeding in
           advance of the final disposition of such action or proceeding, upon
           the Registrant's receipt of the undertaking of the person indemnified
           to repay such payment if such person shall be adjudicated not
           entitled to such indemnification.

           Directors and officers are also insured up to an aggregate amount of
           $15 million under Directors' and Officers' Liability and Company
           Reimbursement Policies.

           The Registrant's Restated Articles of Organization include a
           provision limiting the personal liability of directors of the Company
           to its stockholders for monetary damages for breaches of their
           fiduciary duty to the extent permitted by the Massachusetts Business
           Corporation Law.

Item 7.    Exemption from Registration Claimed
-------    -----------------------------------

           Not applicable.

Item 8.    Exhibits
-------    --------

           Exhibit No.       Description of Exhibit
           -----------       ----------------------

           *4.1              Renewed Rights Agreement, dated as of August 19,
                             1997, between the Registrant and BankBoston N.A.
                             (filed as Exhibit 1 to the Registrant's Current
                             Report on Form 8-K dated August 27, 1997).

           *4.2              Form of Common Stock Certificate (filed as Exhibit
                             4.2 to the Registrant's Annual Report on Form 10-K
                             for the year ended December 31, 1995).

           4.3               Inducement Non-Qualified Stock Option Agreement
                             between the Registrant and John F. Curtis dated
                             August 28, 2003.

           5.1               Opinion of Stephen Korn, General Counsel.

           23.1              Consent of PricewaterhouseCoopers LLP.



                                    Page -4-
<PAGE>

           23.2              Consent of Stephen Korn, General Counsel (included
                             in Exhibit 5.1).

           24.0              Power of Attorney.

*Incorporated herein by reference.

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 the  Registration  Statement (or the most
               recent post-effective  amendment thereof) which,  individually or
               in  the  aggregate,   represents  a  fundamental  change  in  the
               information set forth in the Registration Statement;

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

          Provided,  however,  that  paragraphs  (a)(1)(i) and (a)(1)(ii) do not
          apply if the Registration Statement is on Form S-3 or Form S-8 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 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  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 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  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


                                    Page -5-
<PAGE>

     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.

                                   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 Town of Watertown and Commonwealth of Massachusetts on the
18th day of September, 2003.

                                         IONICS, INCORPORATED


                                         By:    /s/Douglas R. Brown
                                                -------------------
                                                 Douglas R. Brown
                                                 President and
                                                 Chief Executive Officer

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
date indicated.

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


                                  President and
/s/ Douglas R. Brown          Chief Executive Officer      September 18, 2003
--------------------
     Douglas R. Brown      (Principal Executive Officer)


                                 Vice President and
/s/ Daniel M. Kuzmak          Chief Financial Officer      September 18, 2003
--------------------
     Daniel M. Kuzmak      (Principal Financial Officer)


                                Vice President and
/s/ Anthony Di Paola            Corporate Controller       September 18, 2003
--------------------
     Anthony Di Paola      (Principal Accounting Officer)


                                    Page -6-
<PAGE>



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
date indicated.


<TABLE>
<CAPTION>

<S>                                          <C>                   <C>
Date: September  18, 2003                    Director              /s/Douglas R. Brown
                                                                   --------------------------------------------
                                                                   Douglas R. Brown, Director

Date: September  18, 2003                    Director              /s/Stephen L. Brown
                                                                   --------------------------------------------
                                                                   Stephen L. Brown, Director

Date: September  18, 2003            Chairman of the Board and
                                             Director              /s/Arthur L. Goldstein
                                                                   --------------------------------------------
                                                                   Arthur L. Goldstein, Director

Date:  September  18, 2003                   Director
                                                                   --------------------------------------------
                                                                   Kathleen F. Feldstein, Director

Date:  September  18, 2003                   Director              /s/William K. Reilly
                                                                   --------------------------------------------
                                                                   William K. Reilly, Director

Date:  September  18, 2003                   Director              /s/John J. Shields
                                                                   --------------------------------------------
                                                                   John J. Shields, Director

Date:  September  18, 2003                   Director              /s/Daniel I. C. Wang
                                                                   --------------------------------------------
                                                                   Daniel I. C. Wang, Director

Date:  September  18, 2003                   Director              /s/Mark S. Wrighton
                                                                   --------------------------------------------
                                                                   Mark S. Wrighton, Director

Date:  September  18, 2003                   Director              /s/Allen S. Wyett
                                                                   --------------------------------------------
                                                                   Allen S. Wyett, Director

</TABLE>


                                    Page -7-
<PAGE>





<TABLE>
<CAPTION>

                                  EXHIBIT INDEX

                                                                                     Sequentially Numbered
Exhibit No.                         Description of Exhibits                                 Page
-----------                         -----------------------                                 ----

<C>              <C>                                                                         <C>
4.1              Renewed Rights Agreement, dated as of August 19, 1997, between               *
                 the Registrant and BankBoston N.A. (filed as Exhibit 1 to the
                 Registrant's Current Report on Form 8-K dated August 27, 1997).

4.2              Form of Common Stock Certificate (filed as Exhibit 4.2 to the                *
                 Registrant's Annual Report on Form 10-K for the year ended
                 December 31, 1995).

4.3              Inducement Non-Qualified Stock Option Agreement between the
                 Registrant and John F. Curtis dated August 28, 2003.

5.1              Opinion of Stephen Korn, General Counsel.

23.1             Consent of PricewaterhouseCoopers LLP.

23.2             Consent of Stephen Korn, General Counsel (included in Exhibit
                 5.1).

24.0             Power of Attorney.
</TABLE>

*Incorporated herein by reference.
[{"type": "S-8", "sequence": "1", "filename": "s8curtis.txt", "secsgml_size_bytes": 21220}]
{"company-data": {"conformed-name": "IONICS INC", "cik": "0000052466", "assigned-sic": "3559", "irs-number": "042068530", "state-of-incorporation": "MA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-108904", "film-number": "03901074"}, "business-address": {"street1": "65 GROVE ST", "city": "WATERTOWN", "state": "MA", "zip": "02172", "phone": "6179262500"}}
As filed with the Securities and Exchange Commission on September 18, 2003
                              Registration No. 33-

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8

                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                              IONICS, INCORPORATED
             (Exact name of registrant as specified in its charter)

      Massachusetts                                     04-2068530
 (State of incorporation)                  (IRS employer identification number)

                                 65 Grove Street
                       Watertown, Massachusetts 02472-2882
              (Address and zip code of principal executive offices)

                 INDUCEMENT NON-QUALIFIED STOCK OPTION AGREEMENT
                            (Full title of the Plan)

                               Stephen Korn, Esq.
                        Vice President & General Counsel
                              Ionics, Incorporated
                                 65 Grove Street
                       Watertown, Massachusetts 02472-2882
                     (Name and address of agent for service)

                                  617-926-2500
          (Telephone number, including area code, of agent for service)

                                    Page -1-
CALCULATION OF REGISTRATION FEE

                                                                   Proposed           Proposed
                                                                   Maximum            Maximum
                                            Amount to be       Offering Price        Aggregate            Amount of
 Title of Securities to be Registered      Registered (1)         Per Share       Offering Price      Registration Fee
 ------------------------------------      --------------         ---------       --------------      ----------------
Common Stock (Par Value $1.00 Per
Share)                                         200,000             $22.00           $4,400,000             $355.96

Total                                          200,000             $22.00           $4,400,000             $355.96
---------------

(1)      Pursuant to Rule 416(a) under the Securities Act of 1933, this
         Registration Statement shall also cover any additional shares of Common
         Stock which become issuable upon exercise of options granted under the
         Inducement Non-Qualified Stock Option Agreement by reason of any stock
         dividend, stock split, recapitalization or other similar transaction.

                                    Page -2-
PART I

Item 1.    Plan Information

           The documents containing the information specified in this Item 1
           will be sent or given to the Vice President, Strategy and Operations
           of the Registrant, to whom the Inducement Non-Qualified Stock Option
           Agreement was granted on August 28, 2003, as specified by Rule 428(b)
           (1). In accordance with the rules and regulations of the Securities
           and Exchange Commission (the "Commission") and the instructions to
           Form S-8, such documents are not being filed with the Commission
           either as part of this Registration Statement or as prospectuses or
           prospectus supplements pursuant to Rule 424.

Item 2.    Registrant Information and Employee Plan Annual Information

           The documents containing the information specified in this Item 2
           will be sent or given to the Vice President, Strategy and Operations
           as specified by Rule 428(b) (1). In accordance with the rules and
           regulations of the Commission and the instructions to Form S-8, such
           documents are not being filed with the Commission either as part of
           this Registration Statement or as prospectuses or prospectus
           supplements pursuant to Rule 424.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.    Incorporation of Documents by Reference

           The following documents filed with the Commission are incorporated by
           reference in this Prospectus:

          (a)  The Annual  Report of the  Registrant on Form 10-K for the fiscal
               year ended December 31, 2002,  filed with the Commission on March
               31, 2003  pursuant to the  Securities  Exchange  Act of 1934,  as
               amended,  which  contains  audited  financial  statements  of the
               Registrant  for the  fiscal  year ended  December  31,  2002,  as
               amended  by Form  10-K/A  filed with the  Commission  on April 1,
               2003.

           (b)(1) The Quarterly Report of the Registrant on Form 10-Q for the
                  fiscal quarter ended March 31, 2003, filed with the Commission
                  on May 15, 2003 pursuant to the Securities Exchange Act of
                  1934, as amended, which contains unaudited financial
                  statements of the Registrant for the fiscal quarter ended
                  March 31, 2003.

               (2) The Quarterly Report of the Registrant on Form 10-Q for the
                  fiscal quarter ended June 30, 2003, filed with the Commission
                  on August 13, 2003 pursuant to the Securities and Exchange Act
                  of 1934, as amended, which contains unaudited financial
                  statements of the Registrant for the fiscal quarter ended June
                  30, 2003.

          (c)  The section entitled  "Description of Registrant's  Securities to
               be  Registered"   contained  in  the  Registrant's   Registration
               Statement on Form 8-A, filed with the Commission on September 27,
               1990 pursuant to Section 12(g) of the Exchange Act.

               All  documents  subsequently  filed  with the  Commission  by the
               Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the
               Exchange Act, prior to the filing of a  post-effective  amendment
               which indicates that all securities offered herein have been sold
               or which deregisters all securities then remaining unsold,  shall

                                    Page -3-
be deemed to be  incorporated  by reference in this  Registration
               Statement  and to be a part  hereof  from the date of filing such
               documents.

Item 4.    Description of Securities
           -------------------------

           Not applicable.

Item 5.    Interest of Named Experts and Counsel
           -------------------------------------

           The validity of the shares of Common Stock offered hereby will be
           passed upon for the Registrant by Stephen Korn, Esq., Vice President
           and General Counsel of the Registrant. Mr. Korn is the beneficial
           owner of 128,814 shares of Common Stock, including 126,000 shares of
           Common Stock in the form of presently exercisable stock options and
           1,591 shares held in the Ionics Section 401(k) Stock Savings Plan
           (based on August 31, 2003 data).

Item 6.    Indemnification of Directors and Officers
           -----------------------------------------

           The Registrant is permitted by Massachusetts law and required by its
           By-laws to indemnify any director or officer or former director or
           officer against all expenses and liabilities reasonably incurred by
           him in connection with any legal action in which such person is
           involved by reason of his position with the Registrant unless he
           shall have been finally adjudicated in any action, suit or proceeding
           not to have acted in good faith in the reasonable belief that his
           action was in the best interests of the Registrant. Such
           indemnification shall include payment by the Registrant of expenses
           incurred in defending a civil or criminal action or proceeding in
           advance of the final disposition of such action or proceeding, upon
           the Registrant's receipt of the undertaking of the person indemnified
           to repay such payment if such person shall be adjudicated not
           entitled to such indemnification.

           Directors and officers are also insured up to an aggregate amount of
           $15 million under Directors' and Officers' Liability and Company
           Reimbursement Policies.

           The Registrant's Restated Articles of Organization include a
           provision limiting the personal liability of directors of the Company
           to its stockholders for monetary damages for breaches of their
           fiduciary duty to the extent permitted by the Massachusetts Business
           Corporation Law.

Item 7.    Exemption from Registration Claimed
-------    -----------------------------------

           Not applicable.

Item 8.    Exhibits
-------    --------

           Exhibit No.       Description of Exhibit
           -----------       ----------------------

           *4.1              Renewed Rights Agreement, dated as of August 19,
                             1997, between the Registrant and BankBoston N.A.
                             (filed as Exhibit 1 to the Registrant's Current
                             Report on Form 8-K dated August 27, 1997).

           *4.2              Form of Common Stock Certificate (filed as Exhibit
                             4.2 to the Registrant's Annual Report on Form 10-K
                             for the year ended December 31, 1995).

           4.3               Inducement Non-Qualified Stock Option Agreement
                             between the Registrant and John F. Curtis dated
                             August 28, 2003.

           5.1               Opinion of Stephen Korn, General Counsel.

           23.1              Consent of PricewaterhouseCoopers LLP.

                                    Page -4-
23.2              Consent of Stephen Korn, General Counsel (included
                             in Exhibit 5.1).

           24.0              Power of Attorney.

*Incorporated herein by reference.

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 the  Registration  Statement (or the most
               recent post-effective  amendment thereof) which,  individually or
               in  the  aggregate,   represents  a  fundamental  change  in  the
               information set forth in the Registration Statement;

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

          Provided,  however,  that  paragraphs  (a)(1)(i) and (a)(1)(ii) do not
          apply if the Registration Statement is on Form S-3 or Form S-8 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 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  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 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  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

                                    Page -5-
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.

                                   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 Town of Watertown and Commonwealth of Massachusetts on the
18th day of September, 2003.

                                         IONICS, INCORPORATED

                                         By:    /s/Douglas R. Brown
                                                -------------------
                                                 Douglas R. Brown
                                                 President and
                                                 Chief Executive Officer

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
date indicated.

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

                                  President and
/s/ Douglas R. Brown          Chief Executive Officer      September 18, 2003
--------------------
     Douglas R. Brown      (Principal Executive Officer)

                                 Vice President and
/s/ Daniel M. Kuzmak          Chief Financial Officer      September 18, 2003
--------------------
     Daniel M. Kuzmak      (Principal Financial Officer)

                                Vice President and
/s/ Anthony Di Paola            Corporate Controller       September 18, 2003
--------------------
     Anthony Di Paola      (Principal Accounting Officer)

                                    Page -6-
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
date indicated.
Date: September  18, 2003                    Director              /s/Douglas R. Brown
                                                                   --------------------------------------------
                                                                   Douglas R. Brown, Director

Date: September  18, 2003                    Director              /s/Stephen L. Brown
                                                                   --------------------------------------------
                                                                   Stephen L. Brown, Director

Date: September  18, 2003            Chairman of the Board and
                                             Director              /s/Arthur L. Goldstein
                                                                   --------------------------------------------
                                                                   Arthur L. Goldstein, Director

Date:  September  18, 2003                   Director
                                                                   --------------------------------------------
                                                                   Kathleen F. Feldstein, Director

Date:  September  18, 2003                   Director              /s/William K. Reilly
                                                                   --------------------------------------------
                                                                   William K. Reilly, Director

Date:  September  18, 2003                   Director              /s/John J. Shields
                                                                   --------------------------------------------
                                                                   John J. Shields, Director

Date:  September  18, 2003                   Director              /s/Daniel I. C. Wang
                                                                   --------------------------------------------
                                                                   Daniel I. C. Wang, Director

Date:  September  18, 2003                   Director              /s/Mark S. Wrighton
                                                                   --------------------------------------------
                                                                   Mark S. Wrighton, Director

Date:  September  18, 2003                   Director              /s/Allen S. Wyett
                                                                   --------------------------------------------
                                                                   Allen S. Wyett, Director
Page -7-
EXHIBIT INDEX

                                                                                     Sequentially Numbered
Exhibit No.                         Description of Exhibits                                 Page
-----------                         -----------------------                                 ----
4.1              Renewed Rights Agreement, dated as of August 19, 1997, between               *
                 the Registrant and BankBoston N.A. (filed as Exhibit 1 to the
                 Registrant's Current Report on Form 8-K dated August 27, 1997).

4.2              Form of Common Stock Certificate (filed as Exhibit 4.2 to the                *
                 Registrant's Annual Report on Form 10-K for the year ended
                 December 31, 1995).

4.3              Inducement Non-Qualified Stock Option Agreement between the
                 Registrant and John F. Curtis dated August 28, 2003.

5.1              Opinion of Stephen Korn, General Counsel.

23.1             Consent of PricewaterhouseCoopers LLP.

23.2             Consent of Stephen Korn, General Counsel (included in Exhibit
                 5.1).

24.0             Power of Attorney.
*Incorporated herein by reference.