SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   FORM 10-Q/A

                          AMENDMENT NO. 1 TO FORM 10-Q

(Mark One)

    X    Quarterly report pursuant to Section 13 or 15(d) of the Securities
         Exchange Act of 1934:  For the quarterly period ended:  June 30, 2000

                                       OR

         Transition report pursuant to Section 13 or 15(d) of the Securities
         Exchange Act of 1934:  For the transition period from ______ to ______

         Commission file number:  1-7211


                                Ionics, Incorporated
                                --------------------
                (Exact name of registrant as specified in its charter)


         Massachusetts                               04-2068530
         -------------                               ----------
         (State or other jurisdiction             (I.R.S. Employer
         of incorporation or                      Identification No.)
         organization)

                  65 Grove Street, Watertown, Massachusetts 02472
                  -----------------------------------------------
                 (Address of principal executive offices) (Zip Code)

                                 (617) 926-2500
                                 --------------
                 (Registrant's telephone number, including area code)

Former name, former address and formal fiscal year, if changed since last
report:  None

Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days.

         Yes   X                     No

The number of shares  outstanding of the  registrant's  Common Stock on June 30,
2000 was 16,220,390.
<PAGE>

This Amendment No.1 on Form 10-Q/A to the Quarterly Report on Form 10-Q
for the quarterly period ended June 30, 2000 is being filed to amend and restate
Part II, Item 4 to such quarterly report because of the following circumstances.

The Company has been informed by a non-record  beneficial  owner of its
Common Stock that such owner had given voting  instructions  to its voting agent
to withhold votes for certain nominees for election as Class II Directors at the
May 2, 2000 Annual Meeting.  The results  reported in Item 4(a) of the Company's
quarterly  report on Form 10-Q filed on August  14,  2000 were  obtained  from a
final voting report of the  Company's  transfer  agent dated May 8, 2000,  which
does not reflect the receipt by the transfer  agent of such  beneficial  owner's
voting instructions.  The Company has been advised by its transfer agent that to
the transfer agent's knowledge, the transfer agent's procedure for adjusting for
withheld  votes was  followed  with respect to the shares voted on behalf of the
beneficial owner at the Annual Meeting.

Because  the  Company  after an  investigation  is unable to  determine
whether the failure to properly  reflect the beneficial  owner's votes was fully
the responsibility of the beneficial  owner's voting agent, the Company,  solely
at the request of the beneficial owner, has decided to adjust its report on Form
10-Q  concerning  the election of directors at the May 2, 2000 Annual Meeting to
reflect  the giving of effect to the  beneficial  owner's  voting  instructions.
Giving effect to such instructions has no effect on the outcome of the election.
This  adjustment in no way constitutes any statement or agreement of the Company
that its Form 10-Q for the quarter ended June 30, 2000 was incorrect when filed.

Part II, Item 4 of the Quarterly  Report on Form 10-Q for the quarterly
period  ended June 30, 2000 is hereby  amended and  restated in its  entirety as
follows.

Item 4.  Submission of Matters to a Vote of Security Holders

a)  The Annual Meeting of the Stockholders was held on May 2, 2000.

Arnaud de Vitry  d'Avaucourt,  William  E.  Katz,  Daniel I. C. Wang and Mark S.
Wrighton were reelected as Class II Directors for a three-year term.  Continuing
as Class I  Directors  until the 2002  Annual  Meeting  are  Douglas  R.  Brown,
Kathleen F.  Feldstein,  Arthur L.  Goldstein and Carl S. Sloane.  Continuing as
Class III Directors until the 2001 Annual Meeting are William L. Brown,  John J.
Shields and Allen S. Wyett. Each of the Class II Directors received at least the
following votes "for" election and no more than the following votes withheld:

                  Votes for:                        11,398,548
                  Votes withheld:                    1,598,690

b) The other matter  submitted for stockholder  approval was ratification of the
selection of  PricewaterhouseCoopers  LLP as the Company  auditors for 2000. The
following votes were cast.

                  Votes for:                        12,902,884
                  Votes against:                        50,987
                  Abstentions:                          23,367

<PAGE>

                                   SIGNATURES

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.

                                   IONICS, INCORPORATED



Date:  November 3, 2000            By: /s/ Arthur L. Goldstein
                                   ----------------------------------------
                                       Arthur L. Goldstein
                                       Chairman and Chief Executive Officer
                                       (duly authorized officer)



Date: November 3, 2000             By: /s/ Anthony DiPaola
                                   -------------------------------------------
                                       Anthony DiPaola
                                       Vice President and Corporate Controller
                                       (principal accounting officer)