-----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,
 Vf1W7+1GBIOZaVyrR5folfBFkUqfcPJaVBrNWjuNeH5eGoiIBWoZ2uXVigwBD6pR
 KMpuj8SJS3fthaOD0XorMg==

<SEC-DOCUMENT>0001179110-08-016050.txt : 20080827
<SEC-HEADER>0001179110-08-016050.hdr.sgml : 20080827
<ACCEPTANCE-DATETIME>20080827171547
ACCESSION NUMBER:		0001179110-08-016050
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080825
FILED AS OF DATE:		20080827
DATE AS OF CHANGE:		20080827

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NAWAZ AHMED
		CENTRAL INDEX KEY:			0001222715

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34033
		FILM NUMBER:		081042745

	MAIL ADDRESS:	
		STREET 1:		1110 AMERICAN PARKWAY NE
		CITY:			ALLENTOWN
		STATE:			PA
		ZIP:			18109

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:			1231

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-08-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001222715</rptOwnerCik>
            <rptOwnerName>NAWAZ AHMED</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11001 BREN ROAD EAST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MINNETONKA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55343</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>2008-08-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>30000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.21</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects the weighted average price of 30,000 shares of common stock of Digi International Inc. purchased by reporting person in multiple transactions on August 25, 2008 with sale prices ranging from $11.00 to $11.30 per share.  The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Joel Johnson as attorney in fact for Ahmed Nawaz</signatureName>
        <signatureDate>2008-08-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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