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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-06-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000736822</issuerCik>
        <issuerName>IMMUCOR INC</issuerName>
        <issuerTradingSymbol>BLUD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001024155</rptOwnerCik>
            <rptOwnerName>EATZ RALPH A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>P O BOX 5625</rptOwnerStreet1>
            <rptOwnerStreet2>3130 GATEWAY DR P O BOX 5625</rptOwnerStreet2>
            <rptOwnerCity>NORCROSS</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30091-5625</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CSO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $0.10 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-06-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6361</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>304711</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The stock is restricted stock issued pursuant to the Companys 2005 Long Term Incentive Plan.</footnote>
        <footnote id="F2">15,730 of the total represents restricted stock which has not yet vested.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Ralph Eatz, by Rebecca Girod</signatureName>
        <signatureDate>2008-06-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2008-06-05
0
0000736822
IMMUCOR INC
BLUD
0001024155
EATZ RALPH A
P O BOX 5625
3130 GATEWAY DR P O BOX 5625
NORCROSS
GA
30091-5625
0
1
0
0
CSO
Common Stock, $0.10 par value
2008-06-05
4
A
0
6361
0
A
304711
D
The stock is restricted stock issued pursuant to the Companys 2005 Long Term Incentive Plan.
15,730 of the total represents restricted stock which has not yet vested.
Ralph Eatz, by Rebecca Girod
2008-06-16