<PAGE>

                                 EXHIBIT 10.1 - CONFIDENTIAL TREATMENT REQUESTED
                                                --------------------------------
                                      Certain information has been omitted from
                                      this exhibit and filed separately with the
                                      Commission pursuant to a request for
                                      confidential treatment under Rule 24b-2



                                                                  Execution Copy
                                  MODIFICATION
                                       TO
                                  AMENDMENT TO
                      INTERNATIONAL DISTRIBUTION AGREEMENT


         This Modification to Amendment to International Distribution Agreement
(the "Modification") is made as of the 31st day of December, 1999, between
Urologix, Inc., a corporation organized and existing under the laws of the State
of Minnesota ("Urologix"), and Boston Scientific Corporation, a corporation
organized and existing under the laws of Delaware ("BSC").

                                   BACKGROUND

         By an International Distribution Agreement dated as of June 26, 1996
(the "Original Agreement"), Urologix granted BSC the rights and responsibilities
of an exclusive distributor of the Products of Urologix in all areas of the
world except the United States and Japan.

         By an amendment to the Original Agreement dated as of February 26, 1999
(the "Amendment"), Urologix and BSC amended the Original Agreement in order for
Urologix to perform certain market development activities for the Products
primarily in Europe, Eastern Europe, and the Middle East, in exchange for
certain market development amounts paid to Urologix by BSC.

         The term of the First Amendment Period under the Amendment expires on
December 31, 1999 and if the parties do not agree to extend the term of the
Original Agreement, the Amendment and the Original Agreement will then
terminate.

         Urologix and BSC desire to continue the term of the Original Agreement
after December 31, 1999 until June 30, 2001 on the terms and conditions set
forth in this Modification. Capitalized terms used but not defined herein shall
have the respective meanings ascribed to such terms in the Original Agreement as
amended by the Amendment. The Original Agreement as amended by the Amendment and
this Modification is herein collectively referred to as the "Agreement."

                              TERMS AND CONDITIONS

         NOW THEREFORE, in consideration of the mutual promises contained
herein, the parties agree as follows:
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                                 EXHIBIT 10.1 - CONFIDENTIAL TREATMENT REQUESTED
                                                --------------------------------
                                      Certain information has been omitted from
                                      this exhibit and filed separately with the
                                      Commission pursuant to a request for
                                      confidential treatment under Rule 24b-2



         1. Second Amendment Period. The terms of this Modification will apply
from January 1, 2000 through June 30, 2001 (the "Second Amendment Period"),
which period is the remainder of the original term under the Original Agreement.
Accordingly, the term of the Amendment (as amended by this Modification) is
hereby extended through the end of the Second Amendment Period.

         2. Redefinition of Territory. Effective January 1, 2000, the definition
of the term "Territory" under the Original Agreement is revoked and of no
further force or effect. During the Second Amendment Period, the term
"Territory" under the Agreement will mean and, be limited to, the European
Countries listed on Exhibit A.

         3. Market Development Compensation. [Confidential Treatment Requested]

                  3.1 [Confidential Treatment Requested]

                  3.2 [Confidential Treatment Requested]

                  3.3 [Confidential Treatment Requested]

         4. Marketing. Urologix will use such commercial efforts as it deems
satisfactory under the circumstances to solicit the sale of Procedure Kits in
the Territory during the Second Amendment Period.

         5. Procedure. All Products sold to third parties by Urologix in the
Territory during the Second Amendment Period will be sold in accordance with the
following procedures:

                  5.1 New Units. Urologix will determine the price and terms at
         which New Units are sold, and will retain all proceeds from the sales
         of all New Units. If requested, BSC will ship New Units to customers
         designated by Urologix and will invoice those customers on behalf of
         Urologix and remit to Urologix all payments received from those
         customers within 10 days after BSC's receipt of payment for the New
         Unit involved. Urologix will pay BSC $2,000 for each New Unit sold by
         Urologix and shipped by BSC to compensate BSC for its services in
         handling and shipping those New Units and collecting those invoices,
         and will also reimburse BSC for the shipping charges incurred by BSC in
         shipping those New Units.

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                                 EXHIBIT 10.1 - CONFIDENTIAL TREATMENT REQUESTED
                                                --------------------------------
                                      Certain information has been omitted from
                                      this exhibit and filed separately with the
                                      Commission pursuant to a request for
                                      confidential treatment under Rule 24b-2



                  5.2 Procedure Kits. Urologix will determine the price at which
         Procedure Kits are sold. [Confidential Treatment Requested] There are
         no assurances that Urologix will achieve such a gross margin, and
         Urologix will not be penalized in any manner if it does not achieve
         such a gross margin.

                  5.3 Purchase Orders. Urologix will inform BSC of all purchase
         orders received with respect to Procedure Kits within three business
         days of receipt thereof. Within three days after being so informed by
         Urologix, BSC may accept any such Purchase Order in accordance with its
         terms. If BSC so accepts such a Purchase Order, BSC will be responsible
         for the proper and timely shipment of the Procedure Kits involved to,
         and the invoicing of, that customer and for the collection of all
         amounts due BSC from any such sale. If BSC does not so accept any such
         order, Urologix may, at its option, fill that order from Urologix own
         inventory. In that event, Urologix will retain all of the proceeds from
         that particular sale; BSC will not be entitled to any benefits from
         that sale.

                  5.4 Demo Units. Urologix may sell any Demo Units as used
         equipment at such price as may be acceptable to Urologix. Urologix will
         promptly inform BSC of the terms of each such sale, and BSC will be
         responsible for invoicing and collecting payment from those customers.
         [Confidential Treatment Requested] BSC will pay Urologix all amounts
         due Urologix in conjunction with each such sale within 10 days after
         BSC's receipt of payment for the Demo Unit involved. If any user of any
         of the Demo Units (which have not been sold) wishes to discontinue its
         use of a Demo Unit, BSC will pay all expenses incurred in conjunction
         with that Demo Unit being returned to BSC's facility in Beek for
         storage by BSC.

                  5.5 Demonstration Catheters. Urologix may provide Procedure
         Kits from BSC's then existing inventory in Beek, the Netherlands or
         from Urologix' own inventory of Procedure Kits to third parties without
         charge. [Confidential Treatment Requested] Urologix will reimburse BSC
         for all of its shipping costs (including insurance) associated with
         such deliveries within 10 days of receipt from BSC of a statement of
         such costs. BSC will not receive any payment from Urologix in
         conjunction with any such Procedure Kits provided by Urologix out of
         its own inventory of Procedure Kits. Urologix will, in its discretion,
         determine whether any such Procedure Kits will be provided from BSC's
         Beek inventory or from Urologix' own inventory.

                  5.6 Congresses and Trade Shows. Urologix may display the
         Products at congresses and trade shows in Europe and certain other
         areas of the world. If Urologix

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                                 EXHIBIT 10.1 - CONFIDENTIAL TREATMENT REQUESTED
                                                --------------------------------
                                      Certain information has been omitted from
                                      this exhibit and filed separately with the
                                      Commission pursuant to a request for
                                      confidential treatment under Rule 24b-2



         prefers to display the Products at a BSC booth at any of those
         congresses or trade shows, Urologix may do so on terms to be
         coordinated between Urologix and BSC with reasonable lead time and
         planning.

                  5.7 Inventory. BSC may purchase from Urologix from time to
         time, such additional units of any of the Procedure Kits as BSC
         determines may be necessary to enable BSC to fill orders for the sale
         of Procedure Kits on a timely basis; [Confidential Treatment Requested]

         6. Service. Urologix shall be responsible for service of all existing
and future Control Unit placements in the Territory. BSC will pay Urologix for
all parts used in servicing those Control Units but will not provide any other
funding for this activity. Urologix will determine, in its sole discretion, the
nature and extent of the service which it will provide for Control Unit
placements in the Territory.

         7. Amendment Provisions Revoked. Effective January 1, 2000, the
following sections of the Amendment are hereby revoked and of no further force
or effect: Sections 1, 2, 3, 4, 5, 6, 7, 8, and 9.

         8. Amendment Provisions Modified. Effective January 1, 2000, the
following sections of the Amendment are hereby modified as indicated below:

                  8.1 In Section 10, the phrase "in accordance with Section 8
                  hereof" in the third line of Section 10 is hereby deleted.

                  8.2 In Section 13, the date "January 1, 1999" contained in
                  Clause (i) is hereby revised to read "January 1, 2001."

         9. Early Termination. Either party may terminate the Agreement for any
reason at any time during the Second Amendment Period, upon at least 90 days
prior written notice to the other party (an "Early Termination Notice"). If the
term of the Agreement is terminated pursuant to this Section 9, the rights and
obligations of BSC and Urologix thereafter under the Agreement will be as set
forth in Section 13 of the Amendment.

         10. Option to Purchase Control Units. Upon the termination of the
Agreement for any reason, Urologix may, for a period of ninety (90) days
following the effective date of such termination, at its option and by written
notice delivered to BSC within such ninety (90) day period, elect to purchase
from BSC such number of New Units or Demo Units then owned by

                                        4
<PAGE>

                                 EXHIBIT 10.1 - CONFIDENTIAL TREATMENT REQUESTED
                                                --------------------------------
                                      Certain information has been omitted from
                                      this exhibit and filed separately with the
                                      Commission pursuant to a request for
                                      confidential treatment under Rule 24b-2



BSC (taking into account the provisions of Section 3.2 if applicable) as it may
then desire to purchase. [Confidential Treatment Requested] Upon receipt of such
notice and payment, BSC will promptly ship, at Urologix' expense, F.O.B. Beek,
the Netherlands, such New Units and Demo Units so purchased; provided, that in
the event that any Demo Units so purchased are not located in Beek, Urologix
shall be responsible for making all arrangements with respect to, and paying all
costs associated with, retrieving, delivery and shipment of such Demo Units from
their then current location and BSC shall bear no responsibility in connection
therewith, title and all risk of loss with respect to such Demo Units having
passed to Urologix upon BSC's receipt of payment therefore. Urologix will
coordinate retrieval of any Demo Units with BSC personnel to minimize impact on
customer relationships. Urologix will reimburse BSC for all shipping costs
(including insurance) incurred by BSC on Urologix' behalf in connection with
deliveries of New Units and Demo Units pursuant to this Section 10 within ten
days of receipt from BSC of a statement of such costs. NOTWITHSTANDING THE TERMS
OF ANY PURCHASE ORDER, INVOICE OR OTHER DOCUMENT OR STATEMENT (WRITTEN OR ORAL),
WHETHER PRIOR TO, CONTEMPORANEOUS WITH OR SUBSEQUENT TO THE DATE OF THIS
MODIFICATION, ALL SALES OF NEW UNITS AND DEMO UNITS PURSUANT TO THIS SECTION 10
SHALL BE ON AN "AS IS" BASIS EXCEPT THAT ALL NEW UNITS MUST BE SALEABLE AS A NEW
CONTROL UNIT, AND BSC HEREBY DISCLAIMS ANY AND ALL OTHER REPRESENTATIONS AND
WARRANTIES, WHETHER EXPRESS OR IMPLIED, WITH RESPECT TO SUCH NEW UNITS AND DEMO
UNITS, INCLUDING WITHOUT LIMITATION ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE. [Confidential Treatment Requested]

         11. Effect of Modification. Except as modified by this Modification,
the Original Agreement, as amended by the Amendment, remains in full force and
effect.

                                          UROLOGIX, INC.

                                          By  /s/Christopher R. Geyen
                                             ----------------------------------
                                             Its Vice President - Finance

                                          BOSTON SCIENTIFIC CORPORATION

                                          By  /s/Ruby Chandy
                                             ----------------------------------
                                             Its President, Microvasive Urology

                                       5
<PAGE>

                                 EXHIBIT 10.1 - CONFIDENTIAL TREATMENT REQUESTED
                                                --------------------------------
                                      Certain information has been omitted from
                                      this exhibit and filed separately with the
                                      Commission pursuant to a request for
                                      confidential treatment under Rule 24b-2



                          EXHIBIT A TO FIRST AMENDMENT


                                  THE TERRITORY



                                 Benelux
                                 United Kingdom
                                 Norway
                                 Sweden
                                 Denmark
                                 Finland
                                 Germany
                                 Switzerland
                                 Austria
                                 Italy
                                 Spain
                                 France

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