-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 AMXBu5fT9Uot30rgyZzRkiB3g/6Weyahy7fzCU0UjCwNYHHZLQgmVMDol6VcCL0L
 9tMaZIAFXEPMPH3UbRWbrg==

<SEC-DOCUMENT>0001179110-04-018830.txt : 20040928
<SEC-HEADER>0001179110-04-018830.hdr.sgml : 20040928
<ACCEPTANCE-DATETIME>20040928132548
ACCESSION NUMBER:		0001179110-04-018830
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040831
FILED AS OF DATE:		20040928
DATE AS OF CHANGE:		20040928

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NIPARKO KAREN L
		CENTRAL INDEX KEY:			0001245089

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-31257
		FILM NUMBER:		041049226

	MAIL ADDRESS:	
		STREET 1:		380 INTERLOCKEN CRESCENT
		CITY:			BROOMFIELD
		STATE:			CO
		ZIP:			80021

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MCDATA CORP
		CENTRAL INDEX KEY:			0000731502
		STANDARD INDUSTRIAL CLASSIFICATION:	COMMUNICATIONS EQUIPMENT, NEC [3669]
		IRS NUMBER:				841421844
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0131

	BUSINESS ADDRESS:	
		STREET 1:		380 INTERLOCKEN CRESCENT
		CITY:			BROOMFIELD
		STATE:			CO
		ZIP:			80021
		BUSINESS PHONE:		3034609200

	MAIL ADDRESS:	
		STREET 1:		380 INTERLOCKEN CRESCENT
		CITY:			BROOMFIELD
		STATE:			CO
		ZIP:			80021
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-08-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000731502</issuerCik>
        <issuerName>MCDATA CORP</issuerName>
        <issuerTradingSymbol>MCDT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001245089</rptOwnerCik>
            <rptOwnerName>NIPARKO KAREN L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>380 INTERLOCKEN CRESCENT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BROOMFIELD</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80021</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP of Human Resources</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>McDATA Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-08-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1375</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.23</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9696</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares purchased through Employee Stock Purchase Plan</footnote>
        <footnote id="F2">Includes 3,044 shares of restricted stock which vested on 7/1/04</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Karen Niparko</signatureName>
        <signatureDate>2004-09-28</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----