-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0000052466-03-000064.txt : 20030821
<SEC-HEADER>0000052466-03-000064.hdr.sgml : 20030821
<ACCEPTANCE-DATETIME>20030821150610
ACCESSION NUMBER:		0000052466-03-000064
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030820
FILED AS OF DATE:		20030821

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IONICS INC
		CENTRAL INDEX KEY:			0000052466
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				042068530
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		65 GROVE ST
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02172
		BUSINESS PHONE:		6179262500

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GOLDSTEIN ARTHUR L
		CENTRAL INDEX KEY:			0001012104

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07211
		FILM NUMBER:		03860037

	BUSINESS ADDRESS:	
		STREET 1:		C/O IONICS INC
		STREET 2:		PO BOX 9131
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02272
		BUSINESS PHONE:		6177863000

	MAIL ADDRESS:	
		STREET 1:		C/O IONICS CORP
		STREET 2:		PO BOX 9131
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			002272
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>goldstein-aug2003_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<!-- - EDGAR Ease Plus 1.0                                   07/25/03  TT    -->
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
   <periodOfReport>2003-08-20</periodOfReport>
   <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000052466</issuerCik>
        <issuerName>IONICS INC</issuerName>
        <issuerTradingSymbol>ION</issuerTradingSymbol>
   </issuer>
   <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001012104</rptOwnerCik>
            <rptOwnerName>GOLDSTEIN ARTHUR L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IONICS INC</rptOwnerStreet1>
            <rptOwnerStreet2>PO BOX 9131</rptOwnerStreet2>
            <rptOwnerCity>WATERTOWN</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02272</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
         <isDirector>1</isDirector>
         <isOfficer>0</isOfficer>
         <isTenPercentOwner>0</isTenPercentOwner>
         <isOther>0</isOther>
      </reportingOwnerRelationship>
   </reportingOwner>
 <nonDerivativeTable>
   <nonDerivativeTransaction>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
         <value>2003-08-20</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>M</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>20000</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>19.75</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>A</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>306011</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
         <value>2003-08-20</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>F</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>17594</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>22.45</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>288417</value>
            <footnoteId id="F1"/>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
 </nonDerivativeTable>
 <derivativeTable>
   <derivativeTransaction>
      <securityTitle>
         <value>Stock Option (right to buy)</value>
      </securityTitle>
      <conversionOrExercisePrice>
         <value>19.75</value>
      </conversionOrExercisePrice>
      <transactionDate>
         <value>2003-08-20</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>M</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
            <footnoteId id="F2"/>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>20000</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>19.75</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <exerciseDate>
         <value>1993-08-25</value>
      </exerciseDate>
      <expirationDate>
         <value>2003-08-25</value>
      </expirationDate>
      <underlyingSecurity>
         <underlyingSecurityTitle>
           <value>Common Stock</value>
         </underlyingSecurityTitle>
         <underlyingSecurityShares>
           <value>20000</value>
         </underlyingSecurityShares>
      </underlyingSecurity>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>29400</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
           <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </derivativeTransaction>
 </derivativeTable>
   <footnotes>
      <footnote id="F1"> Reporting person also owns indirectly 7586 shares acquired from time to time as a result of reporting person's participation in Ionics Section 401(k) Stock Savings Plan (shares are held in name of trustee)</footnote>

      <footnote id="F2"> Option granted under Ionics, Incorporated 1979 Stock Option Plan in a transaction exempt under Rule 16b-3.</footnote>
   </footnotes>
   <ownerSignature>
      <signatureName>Arthur L. Goldstein</signatureName>
      <signatureDate>2003-08-21</signatureDate>
   </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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