-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 K2NpHvcSrJL+lWpQVKlUApxxt5ZY01VeBTgmWI2NSsVilzpafI0hkcOFTxnuykR3
 tpwt0FH4JNLjwSl6v5phPA==

<SEC-DOCUMENT>0000064892-04-000022.txt : 20040720
<SEC-HEADER>0000064892-04-000022.hdr.sgml : 20040720
<ACCEPTANCE-DATETIME>20040720151248
ACCESSION NUMBER:		0000064892-04-000022
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040716
FILED AS OF DATE:		20040720

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PURKAIT BOBBY
		CENTRAL INDEX KEY:			0001014192

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31744
		FILM NUMBER:		04921977

	BUSINESS ADDRESS:	
		STREET 1:		201 MENTOR DRIVE
		CITY:			SANTA BARBARA
		STATE:			CA
		ZIP:			93111
		BUSINESS PHONE:		8058796000

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MENTOR CORP /MN/
		CENTRAL INDEX KEY:			0000064892
		STANDARD INDUSTRIAL CLASSIFICATION:	ORTHOPEDIC, PROSTHETIC & SURGICAL APPLIANCES & SUPPLIES [3842]
		IRS NUMBER:				410950791
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		201 MENTOR DR
		CITY:			SANTA BARBARA
		STATE:			CA
		ZIP:			93111
		BUSINESS PHONE:		8058796000

	MAIL ADDRESS:	
		STREET 1:		201 MENTOR DR
		CITY:			SANTA BARBARA
		STATE:			CA
		ZIP:			93111
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-07-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000064892</issuerCik>
        <issuerName>MENTOR CORP /MN/</issuerName>
        <issuerTradingSymbol>MNT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001014192</rptOwnerCik>
            <rptOwnerName>PURKAIT BOBBY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>201 MENTOR DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA BARBARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>93111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. VP, Business Development</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock, Option Right to Buy</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>31.63</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-07-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.63</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2005-07-16</value>
            </exerciseDate>
            <expirationDate>
                <value>2014-07-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>355178</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>/s/Adel Michael (attorney-in-fact)</signatureName>
        <signatureDate>2004-07-13</signatureDate>
    </ownerSignature>
</ownershipDocument>

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