<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
    <periodOfReport>2003-08-19</periodOfReport>
    <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000846930</issuerCik>
        <issuerName>DQE INC</issuerName>
        <issuerTradingSymbol>DQE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000918977</rptOwnerCik>
            <rptOwnerName>BOZZONE ROBERT P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1000 SIX PPG PLACE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15222</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>2003-08-18</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>P</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>12700</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>14.06</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>28628</value>
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
          <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
          <value>2003-08-18</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>P</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>9800</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>14.08</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>38428</value>
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
          <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
          <value>2003-08-18</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>P</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>28700</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>14.08</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>67128</value>
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
          <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
          <value>2003-08-18</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>P</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>5500</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>14.10</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>72628</value>
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
          <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
          <value>2003-08-19</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>P</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>31900</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>14.10</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>104528</value>
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
  </nonDerivativeTable>
  <derivativeTable>
  </derivativeTable>
    <ownerSignature>
       <signatureName>/s/ Robert P. Bozzone</signatureName>
       <signatureDate>2003-08-20</signatureDate>
    </ownerSignature>
</ownershipDocument>

