As filed with the Securities and Exchange Commission on September 5, 1996
                                                         Registration No. 333-

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                         -------------------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                                SIS BANCORP, INC.
             (Exact name of Registrant as Specified in Its Charter)

                            Massachusetts 04-3303264
      (State or other jurisdiction of (I.R.S. Employer Identification No.)
                            incorporation or organization)

                                1441 Main Street
                        Springfield, Massachusetts 01102
                    (Address of Principal Executive Offices)

                  SIS Bancorp, Inc. Director Stock Option Plan
                 SIS Bancorp, Inc. Management Stock Option Plan
                SIS Bancorp, Inc. Director Restricted Stock Plan
               SIS Bancorp, Inc. Management Restricted Stock Plan
                            (Full Title of the Plans)

                             MICHAEL E. TUCKER, ESQ.
                    Senior Vice President and General Counsel
                                SIS Bancorp, Inc.
                                1441 Main Street
                        Springfield, Massachusetts 01102
                     (Name and Address of Agent For Service)

                                  (413)748-8000
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                             MICHAEL A. MATZKA, ESQ.
                            Sullivan & Worcester LLP
                             One Post Office Square
                           Boston, Massachusetts 02109
<TABLE>
<CAPTION>
                         CALCULATION OF REGISTRATION FEE
=================================================================================================================================
                                                                  Proposed Maximum        Proposed Maximum
                                              Amount to be       Offering Price Per      Aggregate Offering        Amount of
  Title of Securities to be Registered         Registered              Share                   Price            Registration Fee
<S>                                           <C>               <C>                      <C>                    <C>
Common Stock, $.01 par value                  868,650 (1)       $12.25 to $21.00 (2)        $14,064,825 (2)        $4,849.94
=================================================================================================================================

<FN>
(1)  Consists of 806,250  shares  authorized  under the Stock  Option  Plans and
62,400  unissued  shares  authorized  under the  Restricted  Stock  Plans.  Also
includes an  indeterminate  number of securities which may be issuable by reason
of  a  reorganization,   recapitalization,  exchange  of  shares,  stock  split,
combination  of shares or  dividend  payable in shares of Common  Stock or other
securities, as provided under the plans.

(2)  Pursuant to Rule 457(h) the  offering  price is  calculated  based upon the
exercise  price  with  respect to 589,300  shares  subject to options  currently
outstanding  and, for the  remainder  of the shares,  the average of the bid and
asked  prices of the Common  Stock as reported on the  National  Association  of
Securities Dealers Automated  Quotation,  National Market System on September 4,
1996.
</FN>
</TABLE>


<PAGE>





                                EXPLANATORY NOTE

     This Registration  Statement  contains two parts: the first part contains a
Prospectus  prepared in accordance  with the  requirements of Part I of Form S-3
(in  accordance  with Section C of the General  Instructions  to Form S-8) which
covers  re-offers  and  re-sales  by  the  Selling  Shareholders  listed  in the
Prospectus of shares of Common Stock of the Company  issued or to be issued upon
exercise of options  granted to certain  directors  under the stock option plans
maintained by the Registrant.

     The second part contains information required in the Registration Statement
pursuant to Form S-8.




<PAGE>



                           Prospectus 551,200 Shares
                            -------------------------

                                SIS BANCORP, INC.

                            -------------------------

                                  COMMON STOCK
                           (Par Value $.01 Per Share)
                            -------------------------


     This Prospectus is being used in connection with the offering, from time to
time, by certain shareholders (the "Selling  Shareholders") of SIS Bancorp, Inc.
(the  "Company"),  of up to 551,200 shares (the  "Shares") of common stock,  par
value $.01 per share (the "Common Stock"),  of the Company which may be acquired
by certain  directors and executives of the Company under the SIS Bancorp,  Inc.
Director Restricted Stock Plan and the SIS Bancorp,  Inc. Management  Restricted
Stock Plan (the "Restricted  Stock Plans") or acquired  pursuant to the exercise
of options (the  "Options")  granted to certain  directors and executives of the
Company  under the SIS  Bancorp,  Inc.  Director  Stock  Option Plan and the SIS
Bancorp,  Inc.  Management Stock Option Plan  (collectively,  the "Option Plans"
and,  together with the Restricted Stock Plans,  the "Plans").  The Company will
not  receive  any of the  proceeds  from the sale of the  Shares by the  Selling
Shareholders.

     The Shares may be sold from time to time by the Selling  Shareholders or by
pledgees, donees, transferees or other successors in interest. Such sales may be
made on the National  Association  of Securities  Dealers  Automated  Quotation,
National  Market  System  ("NMS") at prices and at terms then  prevailing  or at
prices related to the then current market price, or in negotiated  transactions.
All discounts,  commissions or fees incurred in connection  with the sale of the
Shares  offered  hereby  will  be  paid by the  Selling  Shareholders  or by the
purchasers of the Shares,  except that the expenses of preparing and filing this
Prospectus  and the  related  Registration  Statement  with the  Securities  and
Exchange  Commission  (the  "Commission"),  and of registering or qualifying the
Shares will be paid by the Company.

     The Selling  Shareholders and any broker executing selling orders on behalf
of the  Selling  Shareholders  may be deemed to be an  "underwriter"  within the
meaning of the Securities  Act of 1933, as amended (the  "Securities  Act"),  in
which event any discounts,  concessions,  or commissions received by such broker
may be deemed to be underwriting commissions under the Securities Act.

 The Common Stock is listed on the NMS. On September 4, 1996,  the closing price
of the Common Stock on the NMS was $21 per share.

  THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
         EXCHANGE COMMISSION, THE FEDERAL DEPOSIT INSURANCE CORPORATION
    OR ANY STATE SECURITIES COMMISSION, NOR HAS THE COMMISSION, CORPORATION,
     OR ANY STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY
  OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

      THE SHARES OF COMMON STOCK OFFERED BY THIS PROSPECTUS ARE NOT SAVINGS
    ACCOUNTS OR DEPOSITS AND ARE NOT INSURED BY THE FEDERAL DEPOSIT INSURANCE
  CORPORATION, THE BANK INSURANCE FUND, THE SAVINGS ASSOCIATION INSURANCE FUND
            OR ANY OTHER GOVERNMENTAL AGENCY, AND INVOLVE INVESTMENT
                 RISK, INCLUDING THE POSSIBLE LOSS OF PRINCIPAL.

                The date of this Prospectus is September 5, 1996.



                                        

<PAGE>



     No  person  has  been  authorized  to give any  information  or to make any
representation  not contained in this  Prospectus,  and, if given or made,  such
information or representation  must not be relied upon as having been authorized
by the  Company.  This  Prospectus  does  not  constitute  an offer to sell or a
solicitation  of an offer to buy any  securities  other  than the  Common  Stock
offered by this  Prospectus or an offer to sell or a solicitation of an offer to
buy such Common Stock in any  jurisdiction  to any person to whom it is unlawful
to make such offer or solicitation in such jurisdiction. Neither the delivery of
this  Prospectus nor any sale made  hereunder  shall,  under any  circumstances,
create  any  implication  that  there has been no change in the  affairs  of the
Company or that the  information  herein is correct as of any time subsequent to
the date hereof.

                                TABLE OF CONTENTS

Section                                                                    Page

Available Information ...................................................     3

Incorporation of Certain Documents by Reference .........................     3

The Company .............................................................     4

Selling Shareholders ....................................................     4

Plan of Distribution ....................................................     6

Indemnification .........................................................     6

Experts .................................................................     7

Legal Matters ...........................................................     7








                                        2

<PAGE>



                              AVAILABLE INFORMATION

     The Company is subject to the informational  requirements of the Securities
Exchange  Act of 1934,  as amended  (the  "Exchange  Act"),  and, in  accordance
therewith,  files reports,  proxy  statements,  and other  information  with the
Commission.  Such  reports,  proxy  statements,  and  other  information  can be
inspected  and  copied at the  public  reference  facilities  maintained  by the
Commission  at 450  Fifth  Street,  N.W.,  Washington,  D.C.  20549,  and at the
following  Regional Offices:  the Northeast  Regional Office,  Seven World Trade
Center,  Suite 1300, New York, New York 10048,  and the Midwest Regional Office,
Citicorp  Center,  500  West  Madison  Street,  Suite  1400,  Chicago,  Illinois
60661-2511.  Copies of such material can be obtained by written request from the
Public  Reference  Section  of  the  Commission  at  450  Fifth  Street,   N.W.,
Washington,  D.C. 20549. The Company files  electronically  with the Commission.
The Commisssion maintains a World Wide Web site (located at  http://www.sec.gov)
that contains  reports,  proxy and information  statements and other information
regarding registrants that file electronically with the Commission.

     A  registration  statement  on Form  S-8,  together  with  all  amendments,
exhibits and  documents  incorporated  therein by reference  (the  "Registration
Statement"),  has been filed with the Commission,  Washington,  D.C.,  under the
Securities  Act,  with respect to the Shares  offered by this  Prospectus.  This
Prospectus does not contain all the  information  set forth in the  Registration
Statement,  certain parts of which are omitted in accordance  with the rules and
regulations of the Commission.  Statements in this Prospectus as to the contents
of exhibits are not necessarily complete, and each statement is qualified in all
respects  by  reference  to the copies of  documents  filed or  incorporated  by
reference as exhibits to the Registration  Statement or otherwise filed with the
Commission. See also "Incorporation of Certain Documents by Reference."

                 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

     The following documents (or parts thereof) filed with the Commission by the
Company are incorporated by reference in this Prospectus:

     (a) The Company's  Registration  Statement on Form 8-A, dated June 4, 1996,
relating to the Common Stock.

     (b) The Company's Current Report on Form 8-K, dated June 21, 1996.

     (c) The Company's Quarterly Report on Form 10-Q, for the quarter ended June
30, 1996.

     All documents filed by the Company  pursuant to Sections  13(a),  13(c), or
15(d) of the  Exchange  Act after the date of this  Prospectus  and prior to the
filing of a post-effective  amendment  indicating that all of the Shares offered
hereby have been sold, or  deregistering  all of the Shares that, at the time of
such post-effective amendment, remain unsold, shall be deemed to be incorporated
by reference in this  Prospectus and to be a part hereof from the date of filing
of  such  documents.   Any  statement   contained  herein  or  in  any  document
incorporated  by reference  herein which is deemed to be modified or superseded,
shall not be deemed,  except as so modified or superseded,  to constitute a part
of this Prospectus.

     The Company  shall  furnish  without  charge to each person,  including any
beneficial  owner,  to whom a copy of this  Prospectus  is  delivered,  upon the
written or oral  request of such person,  copies of any or all of the  documents
which  are  incorporated  by  reference  herein  (other  than  exhibits  to such
documents,  unless such exhibits are specifically incorporated by reference into
such  documents).  Written or telephone  requests for such  documents  should be
directed  to Ting  Chang,  Vice  President,  Investor  Relations  and  Corporate
Planning, SIS Bancorp, Inc., 1441 Main Street, Springfield, Massachusetts 01102,
telephone (413)748- 8000.

                                        3

<PAGE>
                                   THE COMPANY

General

     The  Company  is a  business  corporation  organized  under the laws of The
Commonwealth  of  Massachusetts  on January  18,  1996.  The only  office of the
Company,  and its principal place of business,  is located at the main office of
the Bank at 1441 Main Street, Springfield, Massachusetts 01102 and its telephone
number is (413) 748-8000.

     The  Company was  organized  for the sole  purpose of becoming  the holding
company of Springfield  Institution for Savings (the "Bank"). Upon completion of
the holding  company  formation on June 21, 1996, the Bank became a wholly-owned
subsidiary  of the Company,  which thereby  became a bank holding  company under
federal law.

     The Bank is a  Massachusetts-chartered  savings bank  organized in 1827 and
headquartered in Springfield,  Massachusetts.  The conversion of the Bank from a
savings  bank in mutual form to a savings  bank in stock form was  completed  in
February  1995.  The Bank is engaged  principally  in the business of attracting
deposits  from the general  public and investing  those  deposits in real estate
mortgage,   construction,   consumer  and  commercial   loans,  and  in  various
securities.  The Bank conducts its business from its main office in  Springfield
and from a network of 21 branches in Massachusetts.

     Prior to completion of the bank holding company formation,  the Company had
no business activities and there are no operating business activities  currently
proposed  for the  Company.  In the future,  the Company may become an operating
company or acquire commercial banks or thrift  institutions or companies engaged
in bank-related  activities.  There are no current  agreements or understandings
with  respect to any  acquisition  and no  assurance  can be given that any such
acquisitions  will occur.  Upon  formation of the holding  company,  the Company
acquired  all of the  outstanding  Bank common  stock and received a transfer of
approximately  $250,000  in funds from the Bank.  Pending use of these funds for
other  corporate  purposes,  the Company  intends to invest  these funds in U.S.
government  securities  or other  short-term  investments  permitted by law. The
Company  may enter into a  management  agreement  for the  purpose of  rendering
certain  services  to the  Bank.  No  proposal  and no terms  of any  agreement,
however, have been considered.

Property

     Initially,  the  Company  neither  owns nor  leases  any  real or  personal
property.  Instead,  the Company intends to utilize the premises,  equipment and
furniture of the Bank without the direct payment of any rental fees to the Bank.

Competition

     It is expected that for the near future the primary business of the Company
will be the ongoing business of the Bank. Therefore,  the competitive conditions
to be faced by the  Company  will be the same as  those  faced by the  Bank.  In
addition, many banks and financial institutions have formed holding companies or
may form  holding  companies  in the  future.  It is likely  that these  holding
companies  will attempt to acquire  commercial  banks,  thrift  institutions  or
companies engaged in bank-related activities. The Company,  therefore, will face
competition in undertaking any such acquisitions and in operating  subsequent to
any such acquisitions.

Employees

     At the  present  time,  the  Company  does not intend to employ any persons
other than its  management.  It will utilize the support  staff of the Bank from
time to time  without  the  payment of any fees,  except to the extent as may be
required by applicable law. If the Company acquires other financial institutions
or  pursues  other  lines  of  business,  it may at such  time  hire  additional
employees.

                              SELLING SHAREHOLDERS

     The following table sets forth:  (i) the name of each Selling  Shareholder,
(ii) his or her position(s)  with the Company and its predecessor or affiliates,
over the last three years,  (iii) the number of shares of Common Stock owned (or
subject  to  option)  by  each  Selling  Shareholder  as of  the  date  of  this
Prospectus,  (iv) the number of shares of Common Stock which,  as of the date of
this Prospectus,  may be offered for the account of each Selling  Shareholder by
this  Prospectus  and (v) the  amount of the  class to be owned by each  Selling
Shareholder if such Selling Shareholder were to sell all of the shares of Common


                                        4

<PAGE>

Stock  covered by this  Prospectus.  There can be no  assurance  that any of the
Selling  Shareholders  will  offer  for  sale or sell  any or all of the  Shares
offered by them pursuant to this Prospectus.

<TABLE>
<CAPTION>
                                                                                                              Number   Shares Owned
                                                                                             Shares Owned    of Shares   Following
                                                                                             Prior to This     to be   Completion of
Name                              Position with Company                                       Offering*      Offered     Offering *
- -----------------------------     -----------------------------------------------------     --------------- ----------- ------------
<S>                               <C>                                                        <C>            <C>           <C>
Teresita Alicea                   Director of the Bank                                          10,250**       6,600        3,450**

Frank W. Barrett                  Executive Vice President, Credit and Commercial Lending       89,923(1.6%)  61,000       28,923**
                                  Division, of the Bank, since 1994

Mary E. Boland                    Director of the Bank                                          18,800**       6,600       12,200**

Sister Mary Caritas (Geary) S.P.  Director of the Company and the Bank                          10,675**       6,600        4,075**

Ting Chang                        Vice President, Investor Relations and Corporate Planning of  28,324**      20,000        8,324**
                                  the Company, and,  since 1995,  the Bank; previously
                                  Corporate Planning Officer for the Bank
Donald F. Collins                 Director of the Bank                                          31,300**       6,600       24,700**

B. John Dill                      Executive Vice President of the Bank and President of         68,298(1.2%)  40,000       28,298**
                                  Colebrook Corporation

Gilbert F. Ehmke                  Senior Vice President and Chief Investment Officer of the     30,100**      24,500        5,600**
                                  Company and,  since 1995, the Bank

William B. Hart, Jr.              Director of the Company and, since 1996, the Bank             11,800**       6,600        5,200**

Paulette Henderson-Johnson        Director of the Bank                                           8,925**       6,600        2,325**

Charles L. Johnson                Director of the Company and the Bank                          13,800**       6,600        7,200**

Laura Sotir Katz                  Vice President and Controller of the Company and the Bank      9,005**       6,000        3,005**

F. William Marshall, Jr.          President, Chief Executive Officer and Director of the       179,598(3.1%) 126,800       52,798**
                                  Company and the Bank

Henry J. McWhinnie                Senior Vice President, Human Resources Division, of the       43,682**      30,800       12,882**
                                  Bank, since 1994

John M. Naughton                  Director of the Company and the Bank                          25,000**      10,000       15,000**

Thomas O'Brien                    Director of the Company and, since 1996, the Bank             11,800**       6,600        5,200**

Jeanne Rinaldo                    Senior Vice President, Residential Mortgage Division, of the  40,725**      30,600       10,125**
                                  Bank

Brian Schwartz                    Vice President and Director of Internal Auditing of the Bank,  7,000**       6,000        1,000**
                                  since 1995

Gary P. Shannon                   Director of the Bank                                          14,425**       6,600        7,825**

Stephen A. Shatz                  Director of the Company and the Bank                          23,300**       6,600       16,700**

Christopher A. Sinton             Senior Vice President, Retail Banking Division, of the Bank,  41,111**      31,400        9,711**
                                  since 1995

John H. Southworth                Director of the Bank                                          14,110**       6,600        7,510**

John F. Treanor                   Executive Vice President, Treasurer and Chief Financial       83,298(1.5%)  61,500       21,798**
                                  Officer of the Company and, since 1994, the Bank

Michael E. Tucker                 Senior Vice President, Clerk and General Counsel of the       39,937**      30,000        9,937**
                                  Company and the Bank
<FN>
- ---------
*   =For  purposes  of this  table,  the number of shares  owned  prior to this
     registration  includes  all shares which are  allocated to the  shareholder
     under the Company's Employee Stock Ownership Plan, and those which would be
     owned if all options granted under the Option Plans were exercised.
**  =    Less than one percent.
</FN>
</TABLE>
                                        5

<PAGE>



                              PLAN OF DISTRIBUTION

     The sales of the Shares by the Selling  Shareholders may be effected,  from
time to time,  on the NMS or on any stock  exchange  on which the  Shares may be
listed at the time of sale, in negotiated transactions, or through a combination
of such methods of sale, at fixed prices which may be changed,  at market prices
prevailing  at the time of sale,  at prices  related to such  prevailing  market
prices,  or at  negotiated  prices.  The  Selling  Shareholders  may effect such
transactions  by  selling  Shares  to  or  through   broker-dealers,   and  such
broker-dealers may receive  compensation in the form of discounts,  concessions,
or commissions from the Selling Shareholders and/or the purchasers of Shares for
whom such broker-dealers may act as agent or to whom they sell as principal,  or
both (which compensation as to a particular  broker-dealer might be in excess of
customary commissions).

     The Selling Shareholders and any broker-dealers that act in connection with
the sale of the Shares hereunder might be deemed to be "Underwriters" within the
meaning of Section 2(11) of the Securities Act; any commissions received by them
and any profit realized on the resale of Shares as principals might be deemed to
be underwriting compensation under the Securities Act.

     Any broker-dealer  acquiring Shares from a Selling Shareholder may sell the
Shares either directly,  in its normal market-making  activities,  through or to
other  brokers on a principal or agency  basis,  or to its  customers.  Any such
sales may be at prices then  prevailing  on the NMS,  at prices  related to such
prevailing  market prices,  at negotiated  prices,  or at prices  reflecting the
application of a combination of such methods.

     The Company has advised  the Selling  Shareholders  that  anti-manipulative
Rules  10b-5,  10b-6 and 10b-7  promulgated  under the Exchange Act may apply to
their sales in the market.  The Company has furnished  the Selling  Shareholders
with copies of these rules,  and has informed  the Selling  Shareholders  of the
possible need for them to deliver copies of this  Prospectus in connection  with
their resales of the Shares. The Selling  Shareholders may indemnify any broker-
dealer that  participates in  transactions  involving sale of the Shares against
certain liabilities, including liabilities arising under the Securities Act. Any
commissions  paid or any  discounts or  concessions  allowed to any such broker-
dealers,  and, if any such  broker-dealer  purchases shares as a principal,  any
profits  received on the resale of such Shares may be deemed to be  underwriting
discounts and commissions under the Securities Act.

     Upon the  Company's  being  notified by any Selling  Shareholders  that any
material  arrangement has been entered into with a broker-dealer for the sale of
Shares through a cross or block trade, a supplemental  prospectus  will be filed
under  Rule  424(c)  under the  Securities  Act,  setting  forth the name of the
participating  broker-dealer(s),  the  number of shares  involved,  the price at
which such Shares were sold by the Selling Shareholder,  the commissions paid or
discounts  or  concessions  allowed by the Selling  Shareholder  to such broker-
dealer(s), and where applicable, that such broker-dealer(s), did not conduct any
investigation to verify the information set out in this Prospectus.

     Any Shares which qualify for resale pursuant to Rule 144 promulgated  under
the  Securities  Act may be sold under the Rule  rather  than  pursuant  to this
Prospectus.

     There can be no assurance  that the Selling  Shareholders  will sell all or
even any of the Shares which may be offered by them or any of them hereunder.

                                 INDEMNIFICATION

     The  By-laws  of the  Company  provide  for  the  indemnification  of  each
director,  officer,  employee and agent  against all  expenses  and  liabilities
reasonably  incurred by or imposed on him in connection  with any  proceeding or
threatened  proceeding in which he may become involved by reason of his being or
having been a director or  officer,  so long as such person  acted in good faith
and in a manner  he  reasonably  believed  to be in or not  opposed  to the best
interests of the Company. The By-laws of the Company further provide that (a) if
the Company is merged into or  consolidated  with  another  corporation  and the
Company is not the surviving corporation, the surviving corporation shall assume
the indemnification obligations of the Company under the By-laws with respect to
any action, suit,  proceeding or investigation arising out of or relating to any
actions,  transactions or facts occurring at or prior to the date of such merger
or consolidation;  (b) if the By-laws are invalidated on any ground by any court
of competent jurisdiction,  the Company shall nevertheless indemnify and advance
expenses to each indemnitee as to any expenses (including  reasonable attorneys'
fees), judgments, fines, liabilities,  losses, and amounts paid in settlement in
connection with any action,  suit,  proceeding or investigation,  whether civil,
criminal  or  administrative,  including  an  action  by or in the  right of the
Company,  to the  fullest  extent  permitted  by any  applicable  portion of the
By-laws that have not been  invalidated  and to the fullest extent  permitted by
applicable  law; and (c) if the  Massachusetts  General  Laws are amended  after
adoption of the Company's By-

                                       6


<PAGE>

laws to expand  further the  indemnification  permitted  to an  indemnitee,  the
Company shall indemnify all such persons to the fullest extent  permitted by the
Massachusetts General Laws, as so amended.

     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to  Directors,  officers,  or persons  controlling  the Company
pursuant to the foregoing provisions,  the Company has been informed that in the
opinion  of the SEC  such  indemnification,  in the  event  of any  such  actual
liability under the Securities Act, is against public policy as expressed in the
Securities Act and is therefore unenforceable.

     The  Articles  of the  Company  provide  that its  directors  shall  not be
personally  liable to the Company or its  stockholders  for monetary damages for
breach of fiduciary duty as a director,  except for liability (i) for any breach
of the director's duty of loyalty to the Company or its  stockholders,  (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing  violation of law, (iii) for any unlawful  distributions to stockholders
or loans to officers or directors,  or (iv) for any  transaction  from which the
director derived an improper personal benefit.

                                     EXPERTS

     The consolidated  financial  statements of the Bank as of December 31, 1995
and 1994 and for the two years then ended have been audited by Price  Waterhouse
LLP,  independent  accountants,  and for the year ended December 31, 1993,  have
been audited by Coopers & Lybrand L.L.P., independent accountants,  as set forth
in their  respective  reports,  which are included as exhibits to the  Company's
Registration Statement on Form 8-A dated June 4, 1996. Such financial statements
are  incorporated  by reference in this  Prospectus  upon the  authority of such
firms as experts in accounting and auditing.

                                  LEGAL MATTERS

     The validity of the Common Stock offered hereby will be passed upon for the
Company by Sullivan & Worcester LLP, Boston, Massachusetts.



                                        7

<PAGE>



                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1. Plan Information*

Item 2. Registrant Information and Employee Plan Annual Information*

     *Documents   containing  the  information   required  by  Part  I  of  this
Registration  Statement  will be sent or  given  to  each  Plan  participant  in
accordance  with Rule  428(b)(1).  In accordance with the Note to Part I of Form
S-8, such documents are not filed with the  Securities  and Exchange  Commission
(the  "Commission")  either  as  part  of  this  Registration  Statement  or  as
prospectuses or prospectus supplements.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Certain Documents by Reference

     The following documents (or parts thereof) filed with the Commission by the
Company are incorporated by reference in this Prospectus:

     (a) The Company's  Registration  Statement on Form 8-A, dated June 4, 1996,
relating to the Common Stock.

     (b) The Company's Current Report on Form 8-K, dated June 21, 1996.

     (c) The Company's Quarterly Report on Form 10-Q, for the quarter ended June
30, 1996.

     All documents filed by the Company  pursuant to Sections  13(a),  13(c), or
15(d) of the  Exchange  Act after the date of this  Prospectus  and prior to the
filing of a post-effective  amendment  indicating that all of the Shares offered
hereby have been sold, or  deregistering  all of the Shares that, at the time of
such post-effective amendment, remain unsold, shall be deemed to be incorporated
by reference in this  Prospectus and to be a part hereof from the date of filing
of  such  documents.   Any  statement   contained  herein  or  in  any  document
incorporated  by reference  herein which is deemed to be modified or superseded,
shall not be deemed,  except as so modified or superseded,  to constitute a part
of this Prospectus.

Item 4. Description of Securities

     Not applicable,  as the Common Stock is registered  under Section 12 of the
Securities Exchange Act of 1934.

Item 5. Interests of Named Experts and Counsel

     Not Applicable.

Item 6. Indemnification of Directors and Officers

     The  By-laws  of the  Company  provide  for  the  indemnification  of  each
director,  officer,  employee and agent  against all  expenses  and  liabilities
reasonably  incurred by or imposed on him in connection  with any  proceeding or
threatened  proceeding in which he may become involved by reason of his being or
having been a director or  officer,  so long as such person  acted in good faith
and in a manner  he  reasonably  believed  to be in or not  opposed  to the best
interests of the Company. The By-laws of the Company further provide that (a) if
the Company is merged into or  consolidated  with  another  corporation  and the
Company is not the surviving corporation, the surviving corporation shall assume
the indemnification obligations of the Company under the By-laws with respect to
any action, suit,  proceeding or investigation arising out of or relating to any
actions,  transactions or facts occurring at or prior to the date of such merger
or consolidation;  (b) if the By-laws are invalidated on any ground by any court
of competent jurisdiction,  the Company shall nevertheless indemnify and advance
expenses to each indemnitee as to any expenses (including  reasonable attorneys'
fees), judgments, fines, liabilities,  losses, and amounts paid in settlement in
connection with any action,  suit,  proceeding or investigation,  whether civil,
criminal or administrative, including an action by or in the right of the

                                      II-1

<PAGE>



Company,  to the  fullest  extent  permitted  by any  applicable  portion of the
By-laws that have not been  invalidated  and to the fullest extent  permitted by
applicable  law; and (c) if the  Massachusetts  General  Laws are amended  after
adoption of the Company's Bylaws to expand further the indemnification permitted
to an  indemnitee,  the Company shall  indemnify all such persons to the fullest
extent permitted by the Massachusetts General Laws, as so amended.

     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to  Directors,  officers,  or persons  controlling  the Company
pursuant to the foregoing provisions,  the Company has been informed that in the
opinion  of the SEC  such  indemnification,  in the  event  of any  such  actual
liability under the Securities Act, is against public policy as expressed in the
Securities Act and is therefore unenforceable.

     The  Articles  of the  Company  provide  that its  directors  shall  not be
personally  liable to the Company or its  stockholders  for monetary damages for
breach of fiduciary duty as a director,  except for liability (i) for any breach
of the director's duty of loyalty to the Company or its  stockholders,  (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing  violation of law, (iii) for any unlawful  distributions to stockholders
or loans to officers or directors,  or (iv) for any  transaction  from which the
director derived an improper personal benefit.

Item 7. Exemption from Registration Claimed

     Not Applicable.

Item 8. Exhibits

     The following  exhibits are furnished in connection with this  Registration
Statement:

5        Opinion of Sullivan & Worcester LLP

23.1     Consent of Price Waterhouse LLP

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

23.3     Consent of Sullivan & Worcester LLP (contained in Exhibit 5)

24       Power of Attorney (included on signature pages)


Item 9. Undertakings

(1)  The undersigned registrant hereby undertakes:

     (a) 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;

     (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)(i) and (a)(ii) shall not apply if the
information  required  to be  included in a  post-effective  amendment  by those
paragraphs  is contained in periodic  reports  filed by the Company  pursuant to
Section  13 or Section  15(d) of the  Securities  Exchange  Act of 1934 that are
incorporated by reference in this Registration Statement;


                                      II-2

<PAGE>



     (b) that, for the purpose of determining any liability under the Securities
Act of 1933,  each  such  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; and

     (c) 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.

(2)  The  undersigned  registrant  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 therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

(3) 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 that 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  Securities  Act of 1933 and will be governed by the
final adjudication of such issue.


                                      II-3

<PAGE>


                                   SIGNATURES

     Pursuant to the  requirements of the Securities Act of 1933, the registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing  on Form S-8 and has  duly  caused  this  registration
statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized,  in the City of Springfield,  Commonwealth of Massachusetts,  on the
28th day of August, 1996.

                                       SIS BANCORP, INC.


                                       By:/s/ F. William Marshall, Jr.
                                          F. William Marshall, Jr.,
                                          President and Chief Executive Officer

     The  undersigned  Officers  and  Directors  of  SIS  Bancorp,  Inc.  hereby
severally  constitute F. William  Marshall,  Jr., John F. Treanor and Michael E.
Tucker,  and each of them, acting singly,  our true and lawful attorneys to sign
for us and  in  our  names  in the  capacities  indicated  below  the  Company's
Registration  Statement on Form S-8 and any and all amendments  and  supplements
thereto,  filed with the Securities and Exchange Commission,  granting unto each
of said  attorneys,  acting  singly,  full power and authority to do and perform
each and every act and thing  requisite or necessary to be done in and about the
premises,  as  fully  to all  intents  and  purposes  as he might or could do in
person,  hereby  ratifying and confirming  our  signatures to said  registration
statement  signed by our said  attorneys  and all else that said  attorneys  may
lawfully do and cause to be done by virtue hereof.

     Pursuant  to  the   requirements  of  the  Securities  Act  of  1933,  this
Registration  Statement has been signed below by the following persons on behalf
of the Company and in the capacities and on the dates indicated.

<TABLE>
<CAPTION>
     Signatures                                    Capacity                                          Date


<S>                                       <C>                                                       <C>   
/s/ F. William Marshall, Jr.              President, Chief Executive Officer and Director            August 28, 1996
F. William Marshall, Jr.


/s/ John F. Treanor                       Treasurer, Chief Financial Officer and                     August 28, 1996
John F. Treanor                           principal accounting officer

/s/ Sister Mary Caritas Geary             Director                                                   August 28, 1996
Sister Mary Caritas (Geary) S.P.

/s/ William B. Hart, Jr.                  Director                                                   August 28, 1996
William B. Hart, Jr.

/s/ Charles L. Johnson                    Director                                                   August 28, 1996
Charles L. Johnson

/s/ John M. Naughton                      Director                                                   August 28, 1996
John M. Naughton

/s/ Thomas O'Brien                        Director                                                   August 28, 1996
Thomas O'Brien

/s/ Stephen A. Shatz                      Director                                                   August 28, 1996
Stephen A. Shatz
</TABLE>


                                      II-4
[{"type": "S-8", "sequence": "1", "secsgml_size_bytes": 44755}]
{"company-data": {"conformed-name": "SIS BANCORP INC", "cik": "0001013049", "assigned-sic": "6036", "state-of-incorporation": "MA"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-11443", "film-number": "96626259"}, "business-address": {"street1": "P O BOX 3034", "street2": "1441 MAIN STREET", "city": "SPRINGFIELD", "state": "MA", "zip": "01102-3034", "phone": "4137488000"}}
As filed with the Securities and Exchange Commission on September 5, 1996
                                                         Registration No. 333-

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                         -------------------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                                SIS BANCORP, INC.
             (Exact name of Registrant as Specified in Its Charter)

                            Massachusetts 04-3303264
      (State or other jurisdiction of (I.R.S. Employer Identification No.)
                            incorporation or organization)

                                1441 Main Street
                        Springfield, Massachusetts 01102
                    (Address of Principal Executive Offices)

                  SIS Bancorp, Inc. Director Stock Option Plan
                 SIS Bancorp, Inc. Management Stock Option Plan
                SIS Bancorp, Inc. Director Restricted Stock Plan
               SIS Bancorp, Inc. Management Restricted Stock Plan
                            (Full Title of the Plans)

                             MICHAEL E. TUCKER, ESQ.
                    Senior Vice President and General Counsel
                                SIS Bancorp, Inc.
                                1441 Main Street
                        Springfield, Massachusetts 01102
                     (Name and Address of Agent For Service)

                                  (413)748-8000
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                             MICHAEL A. MATZKA, ESQ.
                            Sullivan & Worcester LLP
                             One Post Office Square
                           Boston, Massachusetts 02109
CALCULATION OF REGISTRATION FEE
=================================================================================================================================
                                                                  Proposed Maximum        Proposed Maximum
                                              Amount to be       Offering Price Per      Aggregate Offering        Amount of
  Title of Securities to be Registered         Registered              Share                   Price            Registration Fee
Common Stock, $.01 par value                  868,650 (1)       $12.25 to $21.00 (2)        $14,064,825 (2)        $4,849.94
=================================================================================================================================
(1)  Consists of 806,250  shares  authorized  under the Stock  Option  Plans and
62,400  unissued  shares  authorized  under the  Restricted  Stock  Plans.  Also
includes an  indeterminate  number of securities which may be issuable by reason
of  a  reorganization,   recapitalization,  exchange  of  shares,  stock  split,
combination  of shares or  dividend  payable in shares of Common  Stock or other
securities, as provided under the plans.

(2)  Pursuant to Rule 457(h) the  offering  price is  calculated  based upon the
exercise  price  with  respect to 589,300  shares  subject to options  currently
outstanding  and, for the  remainder  of the shares,  the average of the bid and
asked  prices of the Common  Stock as reported on the  National  Association  of
Securities Dealers Automated  Quotation,  National Market System on September 4,
1996.
EXPLANATORY NOTE

     This Registration  Statement  contains two parts: the first part contains a
Prospectus  prepared in accordance  with the  requirements of Part I of Form S-3
(in  accordance  with Section C of the General  Instructions  to Form S-8) which
covers  re-offers  and  re-sales  by  the  Selling  Shareholders  listed  in the
Prospectus of shares of Common Stock of the Company  issued or to be issued upon
exercise of options  granted to certain  directors  under the stock option plans
maintained by the Registrant.

     The second part contains information required in the Registration Statement
pursuant to Form S-8.
Prospectus 551,200 Shares
                            -------------------------

                                SIS BANCORP, INC.

                            -------------------------

                                  COMMON STOCK
                           (Par Value $.01 Per Share)
                            -------------------------

     This Prospectus is being used in connection with the offering, from time to
time, by certain shareholders (the "Selling  Shareholders") of SIS Bancorp, Inc.
(the  "Company"),  of up to 551,200 shares (the  "Shares") of common stock,  par
value $.01 per share (the "Common Stock"),  of the Company which may be acquired
by certain  directors and executives of the Company under the SIS Bancorp,  Inc.
Director Restricted Stock Plan and the SIS Bancorp,  Inc. Management  Restricted
Stock Plan (the "Restricted  Stock Plans") or acquired  pursuant to the exercise
of options (the  "Options")  granted to certain  directors and executives of the
Company  under the SIS  Bancorp,  Inc.  Director  Stock  Option Plan and the SIS
Bancorp,  Inc.  Management Stock Option Plan  (collectively,  the "Option Plans"
and,  together with the Restricted Stock Plans,  the "Plans").  The Company will
not  receive  any of the  proceeds  from the sale of the  Shares by the  Selling
Shareholders.

     The Shares may be sold from time to time by the Selling  Shareholders or by
pledgees, donees, transferees or other successors in interest. Such sales may be
made on the National  Association  of Securities  Dealers  Automated  Quotation,
National  Market  System  ("NMS") at prices and at terms then  prevailing  or at
prices related to the then current market price, or in negotiated  transactions.
All discounts,  commissions or fees incurred in connection  with the sale of the
Shares  offered  hereby  will  be  paid by the  Selling  Shareholders  or by the
purchasers of the Shares,  except that the expenses of preparing and filing this
Prospectus  and the  related  Registration  Statement  with the  Securities  and
Exchange  Commission  (the  "Commission"),  and of registering or qualifying the
Shares will be paid by the Company.

     The Selling  Shareholders and any broker executing selling orders on behalf
of the  Selling  Shareholders  may be deemed to be an  "underwriter"  within the
meaning of the Securities  Act of 1933, as amended (the  "Securities  Act"),  in
which event any discounts,  concessions,  or commissions received by such broker
may be deemed to be underwriting commissions under the Securities Act.

 The Common Stock is listed on the NMS. On September 4, 1996,  the closing price
of the Common Stock on the NMS was $21 per share.

  THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
         EXCHANGE COMMISSION, THE FEDERAL DEPOSIT INSURANCE CORPORATION
    OR ANY STATE SECURITIES COMMISSION, NOR HAS THE COMMISSION, CORPORATION,
     OR ANY STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY OR ADEQUACY
  OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

      THE SHARES OF COMMON STOCK OFFERED BY THIS PROSPECTUS ARE NOT SAVINGS
    ACCOUNTS OR DEPOSITS AND ARE NOT INSURED BY THE FEDERAL DEPOSIT INSURANCE
  CORPORATION, THE BANK INSURANCE FUND, THE SAVINGS ASSOCIATION INSURANCE FUND
            OR ANY OTHER GOVERNMENTAL AGENCY, AND INVOLVE INVESTMENT
                 RISK, INCLUDING THE POSSIBLE LOSS OF PRINCIPAL.

                The date of this Prospectus is September 5, 1996.
No  person  has  been  authorized  to give any  information  or to make any
representation  not contained in this  Prospectus,  and, if given or made,  such
information or representation  must not be relied upon as having been authorized
by the  Company.  This  Prospectus  does  not  constitute  an offer to sell or a
solicitation  of an offer to buy any  securities  other  than the  Common  Stock
offered by this  Prospectus or an offer to sell or a solicitation of an offer to
buy such Common Stock in any  jurisdiction  to any person to whom it is unlawful
to make such offer or solicitation in such jurisdiction. Neither the delivery of
this  Prospectus nor any sale made  hereunder  shall,  under any  circumstances,
create  any  implication  that  there has been no change in the  affairs  of the
Company or that the  information  herein is correct as of any time subsequent to
the date hereof.

                                TABLE OF CONTENTS

Section                                                                    Page

Available Information ...................................................     3

Incorporation of Certain Documents by Reference .........................     3

The Company .............................................................     4

Selling Shareholders ....................................................     4

Plan of Distribution ....................................................     6

Indemnification .........................................................     6

Experts .................................................................     7

Legal Matters ...........................................................     7

                                        2
AVAILABLE INFORMATION

     The Company is subject to the informational  requirements of the Securities
Exchange  Act of 1934,  as amended  (the  "Exchange  Act"),  and, in  accordance
therewith,  files reports,  proxy  statements,  and other  information  with the
Commission.  Such  reports,  proxy  statements,  and  other  information  can be
inspected  and  copied at the  public  reference  facilities  maintained  by the
Commission  at 450  Fifth  Street,  N.W.,  Washington,  D.C.  20549,  and at the
following  Regional Offices:  the Northeast  Regional Office,  Seven World Trade
Center,  Suite 1300, New York, New York 10048,  and the Midwest Regional Office,
Citicorp  Center,  500  West  Madison  Street,  Suite  1400,  Chicago,  Illinois
60661-2511.  Copies of such material can be obtained by written request from the
Public  Reference  Section  of  the  Commission  at  450  Fifth  Street,   N.W.,
Washington,  D.C. 20549. The Company files  electronically  with the Commission.
The Commisssion maintains a World Wide Web site (located at  http://www.sec.gov)
that contains  reports,  proxy and information  statements and other information
regarding registrants that file electronically with the Commission.

     A  registration  statement  on Form  S-8,  together  with  all  amendments,
exhibits and  documents  incorporated  therein by reference  (the  "Registration
Statement"),  has been filed with the Commission,  Washington,  D.C.,  under the
Securities  Act,  with respect to the Shares  offered by this  Prospectus.  This
Prospectus does not contain all the  information  set forth in the  Registration
Statement,  certain parts of which are omitted in accordance  with the rules and
regulations of the Commission.  Statements in this Prospectus as to the contents
of exhibits are not necessarily complete, and each statement is qualified in all
respects  by  reference  to the copies of  documents  filed or  incorporated  by
reference as exhibits to the Registration  Statement or otherwise filed with the
Commission. See also "Incorporation of Certain Documents by Reference."

                 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

     The following documents (or parts thereof) filed with the Commission by the
Company are incorporated by reference in this Prospectus:

     (a) The Company's  Registration  Statement on Form 8-A, dated June 4, 1996,
relating to the Common Stock.

     (b) The Company's Current Report on Form 8-K, dated June 21, 1996.

     (c) The Company's Quarterly Report on Form 10-Q, for the quarter ended June
30, 1996.

     All documents filed by the Company  pursuant to Sections  13(a),  13(c), or
15(d) of the  Exchange  Act after the date of this  Prospectus  and prior to the
filing of a post-effective  amendment  indicating that all of the Shares offered
hereby have been sold, or  deregistering  all of the Shares that, at the time of
such post-effective amendment, remain unsold, shall be deemed to be incorporated
by reference in this  Prospectus and to be a part hereof from the date of filing
of  such  documents.   Any  statement   contained  herein  or  in  any  document
incorporated  by reference  herein which is deemed to be modified or superseded,
shall not be deemed,  except as so modified or superseded,  to constitute a part
of this Prospectus.

     The Company  shall  furnish  without  charge to each person,  including any
beneficial  owner,  to whom a copy of this  Prospectus  is  delivered,  upon the
written or oral  request of such person,  copies of any or all of the  documents
which  are  incorporated  by  reference  herein  (other  than  exhibits  to such
documents,  unless such exhibits are specifically incorporated by reference into
such  documents).  Written or telephone  requests for such  documents  should be
directed  to Ting  Chang,  Vice  President,  Investor  Relations  and  Corporate
Planning, SIS Bancorp, Inc., 1441 Main Street, Springfield, Massachusetts 01102,
telephone (413)748- 8000.

                                        3
THE COMPANY

General

     The  Company  is a  business  corporation  organized  under the laws of The
Commonwealth  of  Massachusetts  on January  18,  1996.  The only  office of the
Company,  and its principal place of business,  is located at the main office of
the Bank at 1441 Main Street, Springfield, Massachusetts 01102 and its telephone
number is (413) 748-8000.

     The  Company was  organized  for the sole  purpose of becoming  the holding
company of Springfield  Institution for Savings (the "Bank"). Upon completion of
the holding  company  formation on June 21, 1996, the Bank became a wholly-owned
subsidiary  of the Company,  which thereby  became a bank holding  company under
federal law.

     The Bank is a  Massachusetts-chartered  savings bank  organized in 1827 and
headquartered in Springfield,  Massachusetts.  The conversion of the Bank from a
savings  bank in mutual form to a savings  bank in stock form was  completed  in
February  1995.  The Bank is engaged  principally  in the business of attracting
deposits  from the general  public and investing  those  deposits in real estate
mortgage,   construction,   consumer  and  commercial   loans,  and  in  various
securities.  The Bank conducts its business from its main office in  Springfield
and from a network of 21 branches in Massachusetts.

     Prior to completion of the bank holding company formation,  the Company had
no business activities and there are no operating business activities  currently
proposed  for the  Company.  In the future,  the Company may become an operating
company or acquire commercial banks or thrift  institutions or companies engaged
in bank-related  activities.  There are no current  agreements or understandings
with  respect to any  acquisition  and no  assurance  can be given that any such
acquisitions  will occur.  Upon  formation of the holding  company,  the Company
acquired  all of the  outstanding  Bank common  stock and received a transfer of
approximately  $250,000  in funds from the Bank.  Pending use of these funds for
other  corporate  purposes,  the Company  intends to invest  these funds in U.S.
government  securities  or other  short-term  investments  permitted by law. The
Company  may enter into a  management  agreement  for the  purpose of  rendering
certain  services  to the  Bank.  No  proposal  and no terms  of any  agreement,
however, have been considered.

Property

     Initially,  the  Company  neither  owns nor  leases  any  real or  personal
property.  Instead,  the Company intends to utilize the premises,  equipment and
furniture of the Bank without the direct payment of any rental fees to the Bank.

Competition

     It is expected that for the near future the primary business of the Company
will be the ongoing business of the Bank. Therefore,  the competitive conditions
to be faced by the  Company  will be the same as  those  faced by the  Bank.  In
addition, many banks and financial institutions have formed holding companies or
may form  holding  companies  in the  future.  It is likely  that these  holding
companies  will attempt to acquire  commercial  banks,  thrift  institutions  or
companies engaged in bank-related activities. The Company,  therefore, will face
competition in undertaking any such acquisitions and in operating  subsequent to
any such acquisitions.

Employees

     At the  present  time,  the  Company  does not intend to employ any persons
other than its  management.  It will utilize the support  staff of the Bank from
time to time  without  the  payment of any fees,  except to the extent as may be
required by applicable law. If the Company acquires other financial institutions
or  pursues  other  lines  of  business,  it may at such  time  hire  additional
employees.

                              SELLING SHAREHOLDERS

     The following table sets forth:  (i) the name of each Selling  Shareholder,
(ii) his or her position(s)  with the Company and its predecessor or affiliates,
over the last three years,  (iii) the number of shares of Common Stock owned (or
subject  to  option)  by  each  Selling  Shareholder  as of  the  date  of  this
Prospectus,  (iv) the number of shares of Common Stock which,  as of the date of
this Prospectus,  may be offered for the account of each Selling  Shareholder by
this  Prospectus  and (v) the  amount of the  class to be owned by each  Selling
Shareholder if such Selling Shareholder were to sell all of the shares of Common

                                        4
Stock  covered by this  Prospectus.  There can be no  assurance  that any of the
Selling  Shareholders  will  offer  for  sale or sell  any or all of the  Shares
offered by them pursuant to this Prospectus.
Number   Shares Owned
                                                                                             Shares Owned    of Shares   Following
                                                                                             Prior to This     to be   Completion of
Name                              Position with Company                                       Offering*      Offered     Offering *
- -----------------------------     -----------------------------------------------------     --------------- ----------- ------------
Teresita Alicea                   Director of the Bank                                          10,250**       6,600        3,450**

Frank W. Barrett                  Executive Vice President, Credit and Commercial Lending       89,923(1.6%)  61,000       28,923**
                                  Division, of the Bank, since 1994

Mary E. Boland                    Director of the Bank                                          18,800**       6,600       12,200**

Sister Mary Caritas (Geary) S.P.  Director of the Company and the Bank                          10,675**       6,600        4,075**

Ting Chang                        Vice President, Investor Relations and Corporate Planning of  28,324**      20,000        8,324**
                                  the Company, and,  since 1995,  the Bank; previously
                                  Corporate Planning Officer for the Bank
Donald F. Collins                 Director of the Bank                                          31,300**       6,600       24,700**

B. John Dill                      Executive Vice President of the Bank and President of         68,298(1.2%)  40,000       28,298**
                                  Colebrook Corporation

Gilbert F. Ehmke                  Senior Vice President and Chief Investment Officer of the     30,100**      24,500        5,600**
                                  Company and,  since 1995, the Bank

William B. Hart, Jr.              Director of the Company and, since 1996, the Bank             11,800**       6,600        5,200**

Paulette Henderson-Johnson        Director of the Bank                                           8,925**       6,600        2,325**

Charles L. Johnson                Director of the Company and the Bank                          13,800**       6,600        7,200**

Laura Sotir Katz                  Vice President and Controller of the Company and the Bank      9,005**       6,000        3,005**

F. William Marshall, Jr.          President, Chief Executive Officer and Director of the       179,598(3.1%) 126,800       52,798**
                                  Company and the Bank

Henry J. McWhinnie                Senior Vice President, Human Resources Division, of the       43,682**      30,800       12,882**
                                  Bank, since 1994

John M. Naughton                  Director of the Company and the Bank                          25,000**      10,000       15,000**

Thomas O'Brien                    Director of the Company and, since 1996, the Bank             11,800**       6,600        5,200**

Jeanne Rinaldo                    Senior Vice President, Residential Mortgage Division, of the  40,725**      30,600       10,125**
                                  Bank

Brian Schwartz                    Vice President and Director of Internal Auditing of the Bank,  7,000**       6,000        1,000**
                                  since 1995

Gary P. Shannon                   Director of the Bank                                          14,425**       6,600        7,825**

Stephen A. Shatz                  Director of the Company and the Bank                          23,300**       6,600       16,700**

Christopher A. Sinton             Senior Vice President, Retail Banking Division, of the Bank,  41,111**      31,400        9,711**
                                  since 1995

John H. Southworth                Director of the Bank                                          14,110**       6,600        7,510**

John F. Treanor                   Executive Vice President, Treasurer and Chief Financial       83,298(1.5%)  61,500       21,798**
                                  Officer of the Company and, since 1994, the Bank

Michael E. Tucker                 Senior Vice President, Clerk and General Counsel of the       39,937**      30,000        9,937**
                                  Company and the Bank
- ---------
*   =For  purposes  of this  table,  the number of shares  owned  prior to this
     registration  includes  all shares which are  allocated to the  shareholder
     under the Company's Employee Stock Ownership Plan, and those which would be
     owned if all options granted under the Option Plans were exercised.
**  =    Less than one percent.
5
PLAN OF DISTRIBUTION

     The sales of the Shares by the Selling  Shareholders may be effected,  from
time to time,  on the NMS or on any stock  exchange  on which the  Shares may be
listed at the time of sale, in negotiated transactions, or through a combination
of such methods of sale, at fixed prices which may be changed,  at market prices
prevailing  at the time of sale,  at prices  related to such  prevailing  market
prices,  or at  negotiated  prices.  The  Selling  Shareholders  may effect such
transactions  by  selling  Shares  to  or  through   broker-dealers,   and  such
broker-dealers may receive  compensation in the form of discounts,  concessions,
or commissions from the Selling Shareholders and/or the purchasers of Shares for
whom such broker-dealers may act as agent or to whom they sell as principal,  or
both (which compensation as to a particular  broker-dealer might be in excess of
customary commissions).

     The Selling Shareholders and any broker-dealers that act in connection with
the sale of the Shares hereunder might be deemed to be "Underwriters" within the
meaning of Section 2(11) of the Securities Act; any commissions received by them
and any profit realized on the resale of Shares as principals might be deemed to
be underwriting compensation under the Securities Act.

     Any broker-dealer  acquiring Shares from a Selling Shareholder may sell the
Shares either directly,  in its normal market-making  activities,  through or to
other  brokers on a principal or agency  basis,  or to its  customers.  Any such
sales may be at prices then  prevailing  on the NMS,  at prices  related to such
prevailing  market prices,  at negotiated  prices,  or at prices  reflecting the
application of a combination of such methods.

     The Company has advised  the Selling  Shareholders  that  anti-manipulative
Rules  10b-5,  10b-6 and 10b-7  promulgated  under the Exchange Act may apply to
their sales in the market.  The Company has furnished  the Selling  Shareholders
with copies of these rules,  and has informed  the Selling  Shareholders  of the
possible need for them to deliver copies of this  Prospectus in connection  with
their resales of the Shares. The Selling  Shareholders may indemnify any broker-
dealer that  participates in  transactions  involving sale of the Shares against
certain liabilities, including liabilities arising under the Securities Act. Any
commissions  paid or any  discounts or  concessions  allowed to any such broker-
dealers,  and, if any such  broker-dealer  purchases shares as a principal,  any
profits  received on the resale of such Shares may be deemed to be  underwriting
discounts and commissions under the Securities Act.

     Upon the  Company's  being  notified by any Selling  Shareholders  that any
material  arrangement has been entered into with a broker-dealer for the sale of
Shares through a cross or block trade, a supplemental  prospectus  will be filed
under  Rule  424(c)  under the  Securities  Act,  setting  forth the name of the
participating  broker-dealer(s),  the  number of shares  involved,  the price at
which such Shares were sold by the Selling Shareholder,  the commissions paid or
discounts  or  concessions  allowed by the Selling  Shareholder  to such broker-
dealer(s), and where applicable, that such broker-dealer(s), did not conduct any
investigation to verify the information set out in this Prospectus.

     Any Shares which qualify for resale pursuant to Rule 144 promulgated  under
the  Securities  Act may be sold under the Rule  rather  than  pursuant  to this
Prospectus.

     There can be no assurance  that the Selling  Shareholders  will sell all or
even any of the Shares which may be offered by them or any of them hereunder.

                                 INDEMNIFICATION

     The  By-laws  of the  Company  provide  for  the  indemnification  of  each
director,  officer,  employee and agent  against all  expenses  and  liabilities
reasonably  incurred by or imposed on him in connection  with any  proceeding or
threatened  proceeding in which he may become involved by reason of his being or
having been a director or  officer,  so long as such person  acted in good faith
and in a manner  he  reasonably  believed  to be in or not  opposed  to the best
interests of the Company. The By-laws of the Company further provide that (a) if
the Company is merged into or  consolidated  with  another  corporation  and the
Company is not the surviving corporation, the surviving corporation shall assume
the indemnification obligations of the Company under the By-laws with respect to
any action, suit,  proceeding or investigation arising out of or relating to any
actions,  transactions or facts occurring at or prior to the date of such merger
or consolidation;  (b) if the By-laws are invalidated on any ground by any court
of competent jurisdiction,  the Company shall nevertheless indemnify and advance
expenses to each indemnitee as to any expenses (including  reasonable attorneys'
fees), judgments, fines, liabilities,  losses, and amounts paid in settlement in
connection with any action,  suit,  proceeding or investigation,  whether civil,
criminal  or  administrative,  including  an  action  by or in the  right of the
Company,  to the  fullest  extent  permitted  by any  applicable  portion of the
By-laws that have not been  invalidated  and to the fullest extent  permitted by
applicable  law; and (c) if the  Massachusetts  General  Laws are amended  after
adoption of the Company's By-

                                       6
laws to expand  further the  indemnification  permitted  to an  indemnitee,  the
Company shall indemnify all such persons to the fullest extent  permitted by the
Massachusetts General Laws, as so amended.

     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to  Directors,  officers,  or persons  controlling  the Company
pursuant to the foregoing provisions,  the Company has been informed that in the
opinion  of the SEC  such  indemnification,  in the  event  of any  such  actual
liability under the Securities Act, is against public policy as expressed in the
Securities Act and is therefore unenforceable.

     The  Articles  of the  Company  provide  that its  directors  shall  not be
personally  liable to the Company or its  stockholders  for monetary damages for
breach of fiduciary duty as a director,  except for liability (i) for any breach
of the director's duty of loyalty to the Company or its  stockholders,  (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing  violation of law, (iii) for any unlawful  distributions to stockholders
or loans to officers or directors,  or (iv) for any  transaction  from which the
director derived an improper personal benefit.

                                     EXPERTS

     The consolidated  financial  statements of the Bank as of December 31, 1995
and 1994 and for the two years then ended have been audited by Price  Waterhouse
LLP,  independent  accountants,  and for the year ended December 31, 1993,  have
been audited by Coopers & Lybrand L.L.P., independent accountants,  as set forth
in their  respective  reports,  which are included as exhibits to the  Company's
Registration Statement on Form 8-A dated June 4, 1996. Such financial statements
are  incorporated  by reference in this  Prospectus  upon the  authority of such
firms as experts in accounting and auditing.

                                  LEGAL MATTERS

     The validity of the Common Stock offered hereby will be passed upon for the
Company by Sullivan & Worcester LLP, Boston, Massachusetts.

                                        7
PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1. Plan Information*

Item 2. Registrant Information and Employee Plan Annual Information*

     *Documents   containing  the  information   required  by  Part  I  of  this
Registration  Statement  will be sent or  given  to  each  Plan  participant  in
accordance  with Rule  428(b)(1).  In accordance with the Note to Part I of Form
S-8, such documents are not filed with the  Securities  and Exchange  Commission
(the  "Commission")  either  as  part  of  this  Registration  Statement  or  as
prospectuses or prospectus supplements.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Certain Documents by Reference

     The following documents (or parts thereof) filed with the Commission by the
Company are incorporated by reference in this Prospectus:

     (a) The Company's  Registration  Statement on Form 8-A, dated June 4, 1996,
relating to the Common Stock.

     (b) The Company's Current Report on Form 8-K, dated June 21, 1996.

     (c) The Company's Quarterly Report on Form 10-Q, for the quarter ended June
30, 1996.

     All documents filed by the Company  pursuant to Sections  13(a),  13(c), or
15(d) of the  Exchange  Act after the date of this  Prospectus  and prior to the
filing of a post-effective  amendment  indicating that all of the Shares offered
hereby have been sold, or  deregistering  all of the Shares that, at the time of
such post-effective amendment, remain unsold, shall be deemed to be incorporated
by reference in this  Prospectus and to be a part hereof from the date of filing
of  such  documents.   Any  statement   contained  herein  or  in  any  document
incorporated  by reference  herein which is deemed to be modified or superseded,
shall not be deemed,  except as so modified or superseded,  to constitute a part
of this Prospectus.

Item 4. Description of Securities

     Not applicable,  as the Common Stock is registered  under Section 12 of the
Securities Exchange Act of 1934.

Item 5. Interests of Named Experts and Counsel

     Not Applicable.

Item 6. Indemnification of Directors and Officers

     The  By-laws  of the  Company  provide  for  the  indemnification  of  each
director,  officer,  employee and agent  against all  expenses  and  liabilities
reasonably  incurred by or imposed on him in connection  with any  proceeding or
threatened  proceeding in which he may become involved by reason of his being or
having been a director or  officer,  so long as such person  acted in good faith
and in a manner  he  reasonably  believed  to be in or not  opposed  to the best
interests of the Company. The By-laws of the Company further provide that (a) if
the Company is merged into or  consolidated  with  another  corporation  and the
Company is not the surviving corporation, the surviving corporation shall assume
the indemnification obligations of the Company under the By-laws with respect to
any action, suit,  proceeding or investigation arising out of or relating to any
actions,  transactions or facts occurring at or prior to the date of such merger
or consolidation;  (b) if the By-laws are invalidated on any ground by any court
of competent jurisdiction,  the Company shall nevertheless indemnify and advance
expenses to each indemnitee as to any expenses (including  reasonable attorneys'
fees), judgments, fines, liabilities,  losses, and amounts paid in settlement in
connection with any action,  suit,  proceeding or investigation,  whether civil,
criminal or administrative, including an action by or in the right of the

                                      II-1
Company,  to the  fullest  extent  permitted  by any  applicable  portion of the
By-laws that have not been  invalidated  and to the fullest extent  permitted by
applicable  law; and (c) if the  Massachusetts  General  Laws are amended  after
adoption of the Company's Bylaws to expand further the indemnification permitted
to an  indemnitee,  the Company shall  indemnify all such persons to the fullest
extent permitted by the Massachusetts General Laws, as so amended.

     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to  Directors,  officers,  or persons  controlling  the Company
pursuant to the foregoing provisions,  the Company has been informed that in the
opinion  of the SEC  such  indemnification,  in the  event  of any  such  actual
liability under the Securities Act, is against public policy as expressed in the
Securities Act and is therefore unenforceable.

     The  Articles  of the  Company  provide  that its  directors  shall  not be
personally  liable to the Company or its  stockholders  for monetary damages for
breach of fiduciary duty as a director,  except for liability (i) for any breach
of the director's duty of loyalty to the Company or its  stockholders,  (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing  violation of law, (iii) for any unlawful  distributions to stockholders
or loans to officers or directors,  or (iv) for any  transaction  from which the
director derived an improper personal benefit.

Item 7. Exemption from Registration Claimed

     Not Applicable.

Item 8. Exhibits

     The following  exhibits are furnished in connection with this  Registration
Statement:

5        Opinion of Sullivan & Worcester LLP

23.1     Consent of Price Waterhouse LLP

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

23.3     Consent of Sullivan & Worcester LLP (contained in Exhibit 5)

24       Power of Attorney (included on signature pages)

Item 9. Undertakings

(1)  The undersigned registrant hereby undertakes:

     (a) 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;

     (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)(i) and (a)(ii) shall not apply if the
information  required  to be  included in a  post-effective  amendment  by those
paragraphs  is contained in periodic  reports  filed by the Company  pursuant to
Section  13 or Section  15(d) of the  Securities  Exchange  Act of 1934 that are
incorporated by reference in this Registration Statement;

                                      II-2
(b) that, for the purpose of determining any liability under the Securities
Act of 1933,  each  such  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; and

     (c) 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.

(2)  The  undersigned  registrant  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 therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

(3) 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 that 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  Securities  Act of 1933 and will be governed by the
final adjudication of such issue.

                                      II-3
SIGNATURES

     Pursuant to the  requirements of the Securities Act of 1933, the registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing  on Form S-8 and has  duly  caused  this  registration
statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized,  in the City of Springfield,  Commonwealth of Massachusetts,  on the
28th day of August, 1996.

                                       SIS BANCORP, INC.

                                       By:/s/ F. William Marshall, Jr.
                                          F. William Marshall, Jr.,
                                          President and Chief Executive Officer

     The  undersigned  Officers  and  Directors  of  SIS  Bancorp,  Inc.  hereby
severally  constitute F. William  Marshall,  Jr., John F. Treanor and Michael E.
Tucker,  and each of them, acting singly,  our true and lawful attorneys to sign
for us and  in  our  names  in the  capacities  indicated  below  the  Company's
Registration  Statement on Form S-8 and any and all amendments  and  supplements
thereto,  filed with the Securities and Exchange Commission,  granting unto each
of said  attorneys,  acting  singly,  full power and authority to do and perform
each and every act and thing  requisite or necessary to be done in and about the
premises,  as  fully  to all  intents  and  purposes  as he might or could do in
person,  hereby  ratifying and confirming  our  signatures to said  registration
statement  signed by our said  attorneys  and all else that said  attorneys  may
lawfully do and cause to be done by virtue hereof.

     Pursuant  to  the   requirements  of  the  Securities  Act  of  1933,  this
Registration  Statement has been signed below by the following persons on behalf
of the Company and in the capacities and on the dates indicated.
Signatures                                    Capacity                                          Date
/s/ F. William Marshall, Jr.              President, Chief Executive Officer and Director            August 28, 1996
F. William Marshall, Jr.

/s/ John F. Treanor                       Treasurer, Chief Financial Officer and                     August 28, 1996
John F. Treanor                           principal accounting officer

/s/ Sister Mary Caritas Geary             Director                                                   August 28, 1996
Sister Mary Caritas (Geary) S.P.

/s/ William B. Hart, Jr.                  Director                                                   August 28, 1996
William B. Hart, Jr.

/s/ Charles L. Johnson                    Director                                                   August 28, 1996
Charles L. Johnson

/s/ John M. Naughton                      Director                                                   August 28, 1996
John M. Naughton

/s/ Thomas O'Brien                        Director                                                   August 28, 1996
Thomas O'Brien

/s/ Stephen A. Shatz                      Director                                                   August 28, 1996
Stephen A. Shatz
II-4