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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-08-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000790652</issuerCik>
        <issuerName>IMAGING DIAGNOSTIC SYSTEMS INC /FL/</issuerName>
        <issuerTradingSymbol>IMDS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001575665</rptOwnerCik>
            <rptOwnerName>Shotmeyer Elizabeth</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5307 NW 35 TERRACE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FORT LAUDERDALE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33309</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>CONVERTIBLE PROMISSORY NOTES</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2013-08-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>13100</value>
                    <footnoteId id="F1"/>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityTitle>
                <underlyingSecurityValue>
                    <footnoteId id="F1"/>
                </underlyingSecurityValue>
            </underlyingSecurity>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>57884</value>
                    <footnoteId id="F1"/>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Ms. Shotmeyer sold principal from three Convertible Promissory Notes dated May 18, 2012, June 7, 2012 and July 18, 2012 for a total of $13,100 to an unaffiliated third party on August 5, 2013.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Elizabeth Shotmeyer</signatureName>
        <signatureDate>2013-08-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
