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

    <documentType>5</documentType>
    <periodOfReport>2003-12-01</periodOfReport>
    <notSubjectToSection16>0</notSubjectToSection16>
    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000009626</issuerCik>
        <issuerName>BANK OF NEW YORK CO INC</issuerName>
        <issuerTradingSymbol>BK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001202862</rptOwnerCik>
            <rptOwnerName>SCOTT SAMUEL C III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>CORN PRODUCTS INTERNATIONAL, INC.CORN PR</rptOwnerStreet1>
            <rptOwnerStreet2>5 WESTBROOK CORPORATE CENTER5 WESTBROOK</rptOwnerStreet2>
            <rptOwnerCity>WESTCHESTER</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60154</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 (Par Value $7.50)</value>
      </securityTitle>
      <transactionDate>
          <value>2003-11-06</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>5</transactionFormType>
          <transactionCode>L</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>15.39</value>
          </transactionShares>
          <transactionPricePerShare>
              <value>29.6224</value>
          </transactionPricePerShare>
          <transactionAcquiredDisposedCode>
              <value>A</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>6615.39</value>
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
  </nonDerivativeTable>
  <derivativeTable>
  </derivativeTable>
    <ownerSignature>
       <signatureName>Samuel C. Scott III</signatureName>
       <signatureDate>2004-01-23</signatureDate>
    </ownerSignature>
</ownershipDocument>

