-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 LVxsRJGM1ab/eyA0Mma3D6iJbzPj34cYFBwMkZTSkFimTtqq+/SxZC50b9+n5AUK
 xIK1w2DtCXmeOcNuEUn5tg==

<SEC-DOCUMENT>0001179110-05-014688.txt : 20050722
<SEC-HEADER>0001179110-05-014688.hdr.sgml : 20050722
<ACCEPTANCE-DATETIME>20050722193636
ACCESSION NUMBER:		0001179110-05-014688
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050721
FILED AS OF DATE:		20050722
DATE AS OF CHANGE:		20050722

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DIGI INTERNATIONAL INC
		CENTRAL INDEX KEY:			0000854775
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER COMMUNICATIONS EQUIPMENT [3576]
		IRS NUMBER:				411532464
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		11001 BREN ROAD EAST
		CITY:			MINNETONKA
		STATE:			MN
		ZIP:			55343
		BUSINESS PHONE:		6129123444

	MAIL ADDRESS:	
		STREET 1:		11001 BREN ROAD EAST
		CITY:			MINNETONKA
		STATE:			MN
		ZIP:			55343

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WILLIAMS BRADLEY JAMES
		CENTRAL INDEX KEY:			0001204106

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-17972
		FILM NUMBER:		05970026

	BUSINESS ADDRESS:	
		STREET 1:		11122 AURORA AVE.
		CITY:			DES MOINES
		STATE:			IA
		ZIP:			50322
		BUSINESS PHONE:		5152765900X160

	MAIL ADDRESS:	
		STREET 1:		11122 AURORA AVE
		CITY:			DES MOINES
		STATE:			IA
		ZIP:			50322
</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>2005-07-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000854775</issuerCik>
        <issuerName>DIGI INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>DGII</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001204106</rptOwnerCik>
            <rptOwnerName>WILLIAMS BRADLEY JAMES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>717 NE CASTLETON COURT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ANKENY</rptOwnerCity>
            <rptOwnerState>IA</rptOwnerState>
            <rptOwnerZipCode>50021</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-07-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>13500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>23500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Bradley James Williams</signatureName>
        <signatureDate>2005-07-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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