<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-06-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001013934</issuerCik>
        <issuerName>STRAYER EDUCATION INC</issuerName>
        <issuerTradingSymbol>STRA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001018327</rptOwnerCik>
            <rptOwnerName>KLINSKY STEVEN B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O STRAYER EDUCATION</rptOwnerStreet1>
            <rptOwnerStreet2>712 5TH AVE 23RD FL</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-06-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>875120</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1642120</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series A Convertible Preferred Stock</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>26</value>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-06-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>875120</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F6"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>875120</value>
                    <footnoteId id="F7"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On June 29, 2004, New Mountain Partners, L.P. (&quot;New Mountain&quot;) converted all of its shares of Series A Convertible Preferred Stock of the Issuer (&quot;Series A Preferred Stock&quot;) in accordance with Article 7 of the Articles Supplementary of the Issuer.</footnote>
        <footnote id="F2">The Reporting Person is the sole member of New Mountain GP, LLC, which is the General Partner of New Mountain Investments, L.P., which is the General Partner of New Mountain.</footnote>
        <footnote id="F3">The Series A Preferred Stock is subject to certain restrictions as set forth in the Articles Supplementary of the Issuer, the Shareholders' Agreement, dated as of March 16, 2001, by and between New Mountain and MidOcean Capital Investors, L.P. (as successor to DB Capital Investors, L.P.)(&quot;MidOcean&quot;), the Letter Agreement, dated November 14, 2002, among the Issuer, New Mountain and MidOcean, the February 2004 Letter Agreement, dated February 3, 2004, among the Issuer, New Mountain and MidOcean, and the March 2004 Letter Agreement, dated March 9, 2004, among the Issuer, New Mountain, MidOcean and New Mountain Strayer Trust.</footnote>
        <footnote id="F4">The conversion price of the Series A Preferred Stock is subject to antidilution and other adjustments.</footnote>
        <footnote id="F5">The Series A Preferred Stock is immediately exercisable.</footnote>
        <footnote id="F6">There is no expiration date for the Series A Preferred Stock.</footnote>
        <footnote id="F7">The number of shares of Common Stock underlying the Series A Preferred Stock increases as dividends accumulate and compound on a daily basis.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Steven B. Klinsky</signatureName>
        <signatureDate>2004-06-29</signatureDate>
    </ownerSignature>
</ownershipDocument>

