
<PAGE>

     As filed with the Securities and Exchange Commission on March 24, 1997

                                                   Registration No. 333-
_______________________________________________________________________________
_______________________________________________________________________________

                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D. C.  20549

                             ______________________

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                             ______________________

                             DIGI INTERNATIONAL INC.
             (Exact name of Registrant as specified in its charter)

         DELAWARE                                  41-1532464
     (State or other                             (I.R.S. Employer
     jurisdiction of                           Identification No.)
     incorporation or
      organization)

   11001 BREN ROAD EAST                               55343
  MINNETONKA, MINNESOTA                             (Zip Code)
  (Address of principal
    executive offices)


                             DIGI INTERNATIONAL INC.
                    STOCK OPTION PLAN AS AMENDED AND RESTATED
                            (Full title of the plan)

                               Jonathon E. Killmer
                             Digi International Inc.
                              11001 Bren Road East
                          Minnetonka, Minnesota  55343
                     (Name and address of agent for service)

  Telephone number, including area code, of agent for service:  (612) 912-3444

                             ______________________

                         CALCULATION OF REGISTRATION FEE

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                                                  Proposed
                                    Proposed        maximum
    Title of          Amount         maximum       aggregate     Amount of
  securities to       to be      offering price     offering    registration
  be registered     registered    per share (1)     price (1)       fee
-------------------------------------------------------------------------------
  Common Stock,      500,000
 $.01 par value       shares        $ 6.875       $ 3,437,500    $ 1,041.67
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------

(1)  Estimated solely for the purpose of the registration fee pursuant to
     Rule 457(h)(1) based on the average of the high and low sales prices per
     share of the Registrant's Common Stock on March 21, 1997, as reported on
     the Nasdaq National Market.

-------------------------------------------------------------------------------
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<PAGE>


                             DIGI INTERNATIONAL INC.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.   INCORPORATION OF DOCUMENTS BY REFERENCE.

          The following documents, previously filed (File No. 0-17972) with the
Securities and Exchange Commission (the "Commission") pursuant to the Securities
Exchange Act of 1934, as amended (the "Exchange Act"), are, as of their
respective dates, incorporated in this Registration Statement by reference and
made a part hereof:

          (1)  The latest Annual Report on Form 10-K of Digi International Inc.
               (the "Company") for the fiscal year ended September 30, 1996
               filed pursuant to Section 13 of the Exchange Act.

          (2)  All other reports filed pursuant to Section 13(a) or 15(d) of the
               Exchange Act since the end of the fiscal year covered by the
               Annual Report referred to in (1) above.

          (3)  The description of the Company's Common Stock which is contained
               in the Registration Statement on Form 8-A (File No. 0-17972), as
               amended, filed under the Exchange Act and all amendments and
               reports filed for the purpose of updating such description.

          All reports and other documents subsequently filed by the Company
pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to
the date of this Registration Statement and prior to the filing of a
post-effective amendment which indicates that all of the shares of Common Stock
offered have been sold or which deregisters all shares of the Common Stock then
remaining unsold shall be deemed to be incorporated by reference in and a part
of this Registration Statement from the date of filing of such documents.

          Any statement contained in a document incorporated, or deemed to be
incorporated, by reference herein shall be deemed to be modified or superseded
for purposes of this Registration Statement to the extent that a statement
contained herein or incorporated herein by reference or in any other
subsequently filed document that also is or is deemed to be incorporated by
reference herein modifies or supersedes such statement.  Any statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of this Registration Statement.

ITEM 4.   DESCRIPTION OF SECURITIES.

          Not Applicable.

ITEM 5.   INTERESTS OF NAMED EXPERTS AND COUNSEL.

          Not Applicable.

                                      II-1

<PAGE>


ITEM 6.   INDEMNIFICATION OF DIRECTORS AND OFFICERS.

     Under Delaware law, a corporation may indemnify any person who was or is a
party or is threatened to be made a party to an action (other than an action by
or in the right of the corporation) by reason of his services as a director or
officer of the corporation, or his service, at the corporation's request, as a
director, officer, employee or agent of another corporation or other enterprise,
against expenses (including attorneys' fees) that are actually and reasonably
incurred by him ("Expenses"), and judgments, fines and amounts paid in
settlement that are actually and reasonably incurred by him, in connection with
the defense or settlement of such action, provided that he acted in good faith
and in a manner he reasonably believed to be in or not opposed to the
corporation's best interests, and, with respect to any criminal action or
proceeding, had no reasonable cause to believe that his conduct was unlawful.
Although Delaware law permits a corporation to indemnify any person referred to
above against Expenses in connection with the defense or settlement of an action
by or in the right of the corporation, provided that he acted in good faith and
in a manner he reasonably believed to be in or not opposed to the corporation's
best interests, if such person has been judged liable to the corporation,
indemnification is only permitted to the extent that the Court of Chancery (or
the court in which the action was brought) determines that, despite the
adjudication of liability, such person is entitled to indemnity for such
Expenses as the court deems proper.  The General Corporation Law of the State of
Delaware also provides for mandatory indemnification of any director, officer,
employee or agent against Expenses to the extent such person has been successful
in any proceeding covered by the statute.  In addition, the General Corporation
Law of the State of Delaware provides the general authorization of advancement
of a director's or officer's litigation Expenses in lieu of requiring the
authorization of such advancement by the board of directors in specific cases,
and that indemnification and advancement of Expenses provided by the statute
shall not be deemed exclusive of any other rights to which those seeking
indemnification of Expenses may be entitled under any bylaw, agreement or
otherwise.

     Article V of the By-Laws of the Company and indemnification agreements with
directors and officers of the Company provide for the broad indemnification of
the directors and officers of the Company and for advancement of litigation
Expenses to the fullest extent required or permitted by current Delaware law.

     The Company maintains a policy of directors and officers liability
insurance that reimburses the Company for Expenses that it may incur in
conjunction with the foregoing indemnity provisions and that may provide direct
indemnification to officers and directors where the Company is unable to do so.

     The Certificate of Incorporation of the Company eliminates the personal
liability of a director to the Company or its stockholders for monetary damages
for breach of fiduciary duty as a director, except under certain circumstances
involving certain wrongful acts such as breach of a director's duty of loyalty,
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, for any unlawful acts under Section 174 of the General
Corporation Law of the State of Delaware, or for any transaction from which a
director derives an improper personal benefit.

ITEM 7.   EXEMPTION FROM REGISTRATION CLAIMED.

          Not Applicable.

ITEM 8.   EXHIBITS.

     Exhibit                                 Description
     -------                                 -----------

     4.1            Restated Certificate of Incorporation of the Company
                    (incorporated by reference to Exhibit 3(a) to the Company's
                    Registration Statement on Form S-1 (File No. 33-30725)).


                                      II-2

<PAGE>

     4.2            Amended and Restated By-Laws of the Company (incorporated by
                    reference to Exhibit 3(b) to the Company's Registration
                    Statement on Form S-1 (File No. 33-42384)).

     4.3            Digi International Inc. Stock Option Plan as Amended and
                    Restated.

     5.1            Opinion of Faegre & Benson LLP as to the legality of the
                    shares being registered.

     23.1           Consent of Faegre & Benson LLP (contained in its opinion
                    filed as Exhibit 5.1 to this Registration Statement).

     23.2           Consent of Coopers & Lybrand L.L.P.

     24.1           Powers of Attorney.

ITEM 9.   UNDERTAKINGS.

     A.   The Company hereby undertakes:

          (1)  To file, during any period in which offers or sales are being
     made, a post-effective amendment to this Registration Statement;

               (i)  To include any prospectus required by Section 10(a)(3) of
          the Securities Act of 1933;

               (ii) To reflect in the prospectus any facts or events arising
          after the effective date of the Registration Statement (or the most
          recent post-effective amendment thereof) which, individually or in the
          aggregate, represent a fundamental change in the information set forth
          in the Registration Statement.  Notwithstanding the foregoing, any
          increase or decrease in volume of securities offered (if the total
          dollar value of securities offered would not exceed that which was
          registered) and any deviation from the low or high end of the
          estimated maximum offering range may be reflected in the form of
          prospectus filed with the Commission pursuant to Rule 424(b) if, in
          the aggregate, the changes in volume and price represent no more than
          a twenty percent change in the maximum aggregate offering price set
          forth in the "Calculation of Registration Fee" table in the effective
          Registration Statement; and

               (iii)     To include any material information with respect to the
          plan of distribution not previously disclosed in the Registration
          Statement or any material change to such information in the
          Registration Statement;

PROVIDED, HOWEVER, that paragraphs (A)(1)(i) and (A)(1)(ii) do not apply if the
Registration Statement is on Form S-3 or Form S-8, and the information required
to be included in a post-effective amendment by those paragraphs is contained in
periodic reports filed with or furnished to the Commission by the Company
pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934
that are incorporated by reference in the Registration Statement.

          (2)  That, for the purpose of determining any liability under the
     Securities Act of 1933, each post-effective amendment shall be deemed to be
     a new registration statement relating to the securities offered therein,
     and the offering of such securities at that time shall be deemed to be the
     initial bona fide offering thereof.

                                      II-3

<PAGE>

          (3)  To remove from registration by means of a post-effective
     amendment any of the securities being registered which remain unsold at the
     termination of the offering.

     B.   The Company hereby undertakes that, for purposes of determining any
liability under the Securities Act of 1933, each filing of the Company's annual
report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act
of 1934 (and, where applicable, each filing of an employee benefit plan's annual
report pursuant to Section 15(d) of the Securities  Exchange Act of 1934) that
is incorporated by reference in the Registration Statement shall be deemed to be
a new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     C.   Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Company pursuant to the foregoing provisions, or otherwise, the
Company has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore, unenforceable.  In the event that a claim for indemnification
against such liabilities (other than the payment by the Company of expenses
incurred or paid by a director, officer or controlling person of the Company in
the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Company will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.

                                      II-4

<PAGE>

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, as amended, the
Registrant has duly caused this Registration Statement to be signed on its
behalf by the undersigned, thereunto duly authorized, in the City of Minnetonka,
State of Minnesota, on March 24, 1997.

                              DIGI INTERNATIONAL INC.


                              By   Jerry A. Dusa
                                -----------------------------------------------
                                   Jerry A. Dusa
                                   President, Chief Executive Officer and
                                   Director

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on March 24, 1997.


Signature                                    Title
---------                                    -----


Jerry A. Dusa                      President, Chief Executive Officer and
-------------------------          Director
Jerry A. Dusa                      (Principal Executive Officer)


Jonathon E. Killmer                Vice President, Chief Financial Officer
-------------------------          and Treasurer
Jonathon E. Killmer                (Principal Financial and Accounting Officer)


John P. Schinas*                   Chairman of the Board and Director

Willis K. Drake*                   Director

Richard E. Eichhorn*               Director

Mykola Moroz*                      Director

David Stanley*                     Director

Robert Moe*                        Director


*Jerry A. Dusa, by signing his name hereto, does hereby sign this document on
behalf of each of the above named directors of the Registrant pursuant to powers
of attorney duly executed by such.


                              By   Jerry A. Dusa
                                -----------------------------------------------
                                   Jerry A. Dusa, Attorney in Fact

                                      II-5

<PAGE>

                                INDEX TO EXHIBITS


                                                               Method
     Exhibit                       Description                of Filing
     -------                       -----------                ---------

                                                              Incorporated by
4.1  Restated Certificate of Incorporation of the Company.... Reference

                                                              Incorporated by 
4.2  Amended and Restated By-Laws of the Company............. Reference

4.3  Digi International Inc. Stock Option Plan as Amended     Filed
     and Restated............................................ Electronically


5.1  Opinion of Faegre & Benson LLP                           Filed
     as to the legality of the shares being registered....... Electronically

23.1 Consent of Faegre & Benson LLP (contained in its
     opinion filed as Exhibit 5.1 to this Registration        Filed
     Statement).............................................. Electronically

                                                              Filed
23.2 Consent of Coopers & Lybrand L.L.P. .................... Electronically

                                                              Filed
24   Powers of Attorney. .................................... Electronically



                                      II-6
