<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>
    <periodOfReport>2003-07-22</periodOfReport>
    <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000087777</issuerCik>
        <issuerName>SCIENTIFIC ATLANTA INC</issuerName>
        <issuerTradingSymbol>SFA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001232620</rptOwnerCik>
            <rptOwnerName>EIDSON JULIAN W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP and Controller</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>
   <nonDerivativeSecurity>
      <securityTitle>
          <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
          <value>2003-07-22</value>
      </transactionDate>
      <transactionCoding>
          <transactionFormType>4</transactionFormType>
          <transactionCode>S</transactionCode>
          <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionTimeliness>
      <value />
      </transactionTimeliness>
      <transactionAmounts>
          <transactionShares>
              <value>10000</value>
          </transactionShares>
          <transactionValue>
              <value>31.02</value>
          </transactionValue>
          <transactionAcquiredDisposedCode>
              <value>D</value>
          </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
          <sharesOwnedFollowingTransaction>
              <value>70052</value>
              <footnoteId id="F1" />
          </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
          <directOrIndirectOwnership>
              <value>D</value>
          </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeSecurity>
<footnotes>
   <footnote id="F1">Indirectly holds 2,089 shares in Company's 401(k) plan based on June 30, 2003 statement and includes Company matches in the Scientific-Atlanta stock fund as of such date.  The number of shares may fluctuate up or down depending on the performance of the Scientific-Atlanta stock fund in the 401(k) plan.</footnote>
</footnotes>
    <ownerSignature>
       <signatureName>Julian W Eidson</signatureName>
       <signatureDate>2003-07-24</signatureDate>
    </ownerSignature>
    <ownerSignature>
       <signatureName>P Van Gorder, by Power of Atty</signatureName>
       <signatureDate>2003-07-24</signatureDate>
    </ownerSignature>
</ownershipDocument>

