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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 0ho1oLVsqvepNCN8x4iMYw==

<SEC-DOCUMENT>0001271965-04-000004.txt : 20040315
<SEC-HEADER>0001271965-04-000004.hdr.sgml : 20040315
<ACCEPTANCE-DATETIME>20040315121553
ACCESSION NUMBER:		0001271965-04-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040311
FILED AS OF DATE:		20040315

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			O NEIL ROBERT A
		CENTRAL INDEX KEY:			0001271965

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21969
		FILM NUMBER:		04668444

	BUSINESS ADDRESS:	
		STREET 1:		CIENA CORP.
		STREET 2:		1201 WINTERSON RD.
		CITY:			LINTHICUM
		STATE:			MD
		ZIP:			21090

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CIENA CORP
		CENTRAL INDEX KEY:			0000936395
		STANDARD INDUSTRIAL CLASSIFICATION:	TELEPHONE & TELEGRAPH APPARATUS [3661]
		IRS NUMBER:				232725311
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1031

	BUSINESS ADDRESS:	
		STREET 1:		1201 WINTERSON ROAD
		CITY:			LINTHICUM
		STATE:			MD
		ZIP:			21090
		BUSINESS PHONE:		4108658500

	MAIL ADDRESS:	
		STREET 1:		1201 WINTERSON ROAD
		CITY:			LINTHICUM
		STATE:			MD
		ZIP:			21090
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-03-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000936395</issuerCik>
        <issuerName>CIENA CORP</issuerName>
        <issuerTradingSymbol>CIEN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001271965</rptOwnerCik>
            <rptOwnerName>O NEIL ROBERT A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1201 WINTERSON ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LINTHICUM</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21090</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP Sales, Data Networking Grp</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-03-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>350000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.68</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>335731</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">50,650 shares are held in escrow pursuant to the merger agreement by and between WaveSmith and CIENA; 186,564 are restricted shares and are held in a book account at the Transfer Agent which will vest and be distributed to Mr. O'Neil by November 18, 2005; and 98,517 are held by Mr. O'Neil without restriction.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Robert O'Neil/Anita Weiskerger by POA</signatureName>
        <signatureDate>2004-03-15</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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