<SUBMISSION>
<ACCESSION-NUMBER>0001140437-03-000438
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20031219
<FILING-DATE>20031223
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>AMERICAN PACIFIC CORP
<CIK>0000350832
<ASSIGNED-SIC>2810
<IRS-NUMBER>596490478
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>0930
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>3770 HOWARD HUGHES PKWY STE 300
<CITY>LAS VEGAS
<STATE>NV
<ZIP>89109
<PHONE>7027352200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>3770 HOWARD HUGHES PKWY STE 300
<STREET2>3770 HOWARD HUGHES PKWY STE 300
<CITY>LAS VEGAS
<STATE>NV
<ZIP>89109
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>KEYS DAVID N
<CIK>0001267667
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-08137
<FILM-NUMBER>031070535
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>3770 HOWARD HUGHES PARKWAY
<STREET2>SUITE 300
<CITY>LAS VEGAS
<STATE>NV
<ZIP>89109
<PHONE>702-735-2200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>3770 HOWARD HUGHES PARKWAY
<STREET2>STE 300
<CITY>LAS VEGAS
<STATE>NV
<ZIP>89109
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ap906708_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>2003-12-19</periodOfReport>
   <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000350832</issuerCik>
        <issuerName>AMERICAN PACIFIC CORP</issuerName>
        <issuerTradingSymbol>apfc</issuerTradingSymbol>
   </issuer>
   <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001267667</rptOwnerCik>
            <rptOwnerName>KEYS DAVID N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3770 HOWARD HUGHES PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>LAS VEGAS</rptOwnerCity>
            <rptOwnerState>NV</rptOwnerState>
            <rptOwnerZipCode>89109</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
         <isDirector>1</isDirector>
         <isOfficer>1</isOfficer>
         <isTenPercentOwner>0</isTenPercentOwner>
         <isOther>0</isOther>
         <officerTitle>EVP,CFO, Treasurer &amp; Secretary</officerTitle>
      </reportingOwnerRelationship>
   </reportingOwner>
 <nonDerivativeTable>
   <nonDerivativeTransaction>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
         <value>2003-12-19</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>M</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>17000</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>7.781</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>A</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>19000</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
         <value>2003-12-19</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>M</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>45000</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>8.30</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>A</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>64000</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
         <value>2003-12-19</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>S</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>56500</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>9.715</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>7500</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
 </nonDerivativeTable>
 <derivativeTable>
   <derivativeTransaction>
      <securityTitle>
         <value>Options to Purchase</value>
      </securityTitle>
      <conversionOrExercisePrice>
         <value>7.781</value>
      </conversionOrExercisePrice>
      <transactionDate>
         <value>2003-12-19</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>X</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>17000</value>
         </transactionShares>
         <transactionPricePerShare>
            <footnoteId id="F1"/>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <exerciseDate>
         <value>2000-09-14</value>
      </exerciseDate>
      <expirationDate>
         <value>2005-09-14</value>
      </expirationDate>
      <underlyingSecurity>
         <underlyingSecurityTitle>
           <value>Common Stock</value>
         </underlyingSecurityTitle>
         <underlyingSecurityShares>
           <value>17000</value>
         </underlyingSecurityShares>
      </underlyingSecurity>
      <postTransactionAmounts>
         <valueOwnedFollowingTransaction>
           <value>0</value>
         </valueOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
           <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </derivativeTransaction>
   <derivativeTransaction>
      <securityTitle>
         <value>Options to Purchase</value>
      </securityTitle>
      <conversionOrExercisePrice>
         <value>8.30</value>
      </conversionOrExercisePrice>
      <transactionDate>
         <value>2003-12-19</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>X</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>22500</value>
         </transactionShares>
         <transactionPricePerShare>
            <footnoteId id="F1"/>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <exerciseDate>
         <value>2002-12-13</value>
      </exerciseDate>
      <expirationDate>
         <value>2012-12-13</value>
      </expirationDate>
      <underlyingSecurity>
         <underlyingSecurityTitle>
           <value>Common Stock</value>
         </underlyingSecurityTitle>
         <underlyingSecurityShares>
           <value>22500</value>
         </underlyingSecurityShares>
      </underlyingSecurity>
      <postTransactionAmounts>
         <valueOwnedFollowingTransaction>
           <value>0</value>
         </valueOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
           <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </derivativeTransaction>
   <derivativeTransaction>
      <securityTitle>
         <value>Options to Purchase</value>
      </securityTitle>
      <conversionOrExercisePrice>
         <value>8.30</value>
      </conversionOrExercisePrice>
      <transactionDate>
         <value>2003-12-19</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>X</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>22500</value>
         </transactionShares>
         <transactionPricePerShare>
            <footnoteId id="F1"/>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <exerciseDate>
         <value>2003-12-13</value>
      </exerciseDate>
      <expirationDate>
         <value>2012-12-13</value>
      </expirationDate>
      <underlyingSecurity>
         <underlyingSecurityTitle>
           <value>Common Stock</value>
         </underlyingSecurityTitle>
         <underlyingSecurityShares>
           <value>22500</value>
         </underlyingSecurityShares>
      </underlyingSecurity>
      <postTransactionAmounts>
         <valueOwnedFollowingTransaction>
           <value>0</value>
         </valueOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
           <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </derivativeTransaction>
 </derivativeTable>
   <footnotes>
      <footnote id="F1"> Omitted in accordance with General Instructions for Form 4, Rule 4(c)(iii).</footnote>
   </footnotes>
   <ownerSignature>
      <signatureName>David N. Keys</signatureName>
      <signatureDate>2003-12-23</signatureDate>
   </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
