As filed with the Securities and Exchange Commission on May 6, 1998
                                                   Registration No. 333-

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

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

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

        Massachusetts                                 04-3308902
(State or other jurisdiction of         (I.R.S. Employer  Identification No.)
incorporation or organization)

                              222 Merrimack Street
                           Lowell, Massachusetts 01852
                    (Address of Principal Executive Offices)

                 Enterprise Bancorp, Inc. 1988 Stock Option Plan
               Enterprise Bancorp, Inc. 1998 Stock Incentive Plan
                            (Full Title of the Plans)

                               JOHN P. CLANCY, JR.
                                    Treasurer
                            Enterprise Bancorp, Inc.
                              222 Merrimack Street
                           Lowell, Massachusetts 01852
                     (Name and Address of Agent For Service)

                                 (978) 459-9000
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                             STEPHEN J. COUKOS, 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                    227,287 (1)         $11.00 to $18.00 (2)     $3,180,263.50 (2)          $938.18
<FN>
(1) Consists of 148,477 shares that remain authorized for issuance under the 1988 Stock Option Plan and 78,810 shares authorized for
issuance under the 1998 Stock Incentive Plan. 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 148,375 shares subject
to options currently outstanding and, for the remainder of the shares, the book value of the Common Stock as of March 31, 1998.
</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 the  Company's  Common  Stock  that may be issued  upon
exercise of options  granted to certain  executive  officers under the Company's
1988 Stock Option Plan as well as shares of the Company's  Common Stock that may
be issued  either  directly  or upon  exercise  of  options  granted  to certain
executive officers and directors under the Company's 1998 Stock Incentive Plan.

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




<PAGE>

Prospectus

                                  83,850 Shares
                            -------------------------

                            ENTERPRISE 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  Enterprise
Bancorp,  Inc. (the "Company"),  of up to 83,850 shares (the "Shares") of common
stock, par value $.01 per share (the "Common Stock"), of the Company,  which may
be acquired by certain executive  officers pursuant to their exercise of options
granted by the Company under the Enterprise Bancorp, Inc. 1988 Stock Option Plan
(the "Plan").  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 Nasdaq Stock Market, a stock exchange or other market system, if and
to the extent that the Common  Stock is then listed or otherwise  qualified  for
trading thereon,  at prices and on 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 not presently listed or otherwise qualified for trading
on the Nasdaq Stock Market, any stock exchange or any other market system.

  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 May 6, 1998.

<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

Risk Factors .....................................................     4

Selling Shareholders .............................................     5

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 July 16, 1996,
relating to the Common Stock.

     (b) The Company's Annual Report on Form 10-KSB, for the year ended December
31, 1997.

     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 John P.  Clancy,  Jr.,  Treasurer,  Enterprise  Bancorp,  Inc.,  222
Merrimack Street, Lowell, Massachusetts 01852, telephone (978) 459-9000.

                                        3
<PAGE>

                                   THE COMPANY

General

     The  Company  is a  business  corporation  organized  under the laws of the
Commonwealth  of  Massachusetts  on February  29,  1996.  The only office of the
Company,  and its principal place of business,  is located at the main office of
Enterprise Bank and Trust Company (the "Bank") at 222 Merrimack Street,  Lowell,
Massachusetts 01852 and its telephone number is (978) 459-9000.

     The  Company was  organized  for the sole  purpose of becoming  the holding
company of the Bank. Upon  completion of the holding  company  formation on July
26,  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  trust  company,  which  commenced
business on January 3, 1989, and is headquartered in Lowell, Massachusetts.  The
Bank offers a range of  commercial,  consumer and trust  services with a goal of
satisfying  the  needs of  consumers,  small  and  medium-sized  businesses  and
professionals. The Bank conducts its business from its main office in Lowell and
from a network of 5  additional  branches in the  Massachusetts  communities  of
Chelmsford, Billerica, Leominster, Tewksbury and Dracut.

     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 or otherwise  permissible  nonbanking  activities.  There are no
current agreements or understandings with respect to any such acquisition and no
assurance can be given that any such future acquisitions will occur.

Property

     The  Company  neither  owns nor leases any real or personal  property.  The
Company  utilizes  the  premises,  equipment  and  furniture of the Bank on a de
minimis basis 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. The Bank
faces strong  competition  to attract  deposits and to generate  loans.  Several
major commercial banks are  headquartered  in neighboring  Boston,  and numerous
other commercial  banks,  savings banks,  cooperative  banks,  credit unions and
savings and loan  associations have one or more offices in Greater Lowell and in
the  Leominster/Fitchburg,  Massachusetts  area. The major commercial banks have
several  competitive  advantages  over the Bank,  including  the ability to make
larger loans to a single  borrower  than is possible  for the Bank.  The greater
financial  resources  of these  banks also allows them to offer a broad range of
automated  banking  services,  to maintain  numerous branch offices and to mount
extensive  advertising  and  promotional  campaigns.  Competition  for loans and
deposits  also comes from other  businesses  which provide  financial  services,
including  consumer finance  companies,  factors,  mortgage  brokers,  insurance
companies,  securities  brokerage  firms,  money market mutual funds and private
lenders.  Notwithstanding the substantial  competition facing the Bank, however,
management  believes  that the Bank has  established  a market  niche in Greater
Lowell and the Leominster/Fitchburg area which has been enhanced in recent years
by the acquisition of other independent  banks by major bank holding  companies,
and the resultant  consolidation of competitors' banking operations and services
within the Bank's market area.

Employees

     At the present  time,  the Company  does not employ any persons  other than
through the Bank.  The Company  utilizes the support staff of the Bank from time
to time without the payment of any fees, except as may be otherwise  required by
law. If the Company acquires other financial institutions or pursues other lines
of business, it may at such time hire additional employees.

                                  RISK FACTORS

     No Assurance of Public  Trading  Market.  The Common Stock is not listed or
otherwise  qualified for trading on the Nasdaq Stock Market,  any stock exchange
or any other  market  system.  No assurance  can be given that a public  trading
market for the

                                        4
<PAGE>

Common  Stock will  develop in the  future.  Consequently,  any  purchase of the
Shares may constitute a long-term, illiquid investment.

                              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 predecessors 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
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
                                                                                                    of Shares         Following
                                                                           Shares Owned Prior         to be         Completion of
Name                      Position with Company                             to This Offering*        Offered         Offering *
------------------------  --------------------------------------------- ------------------------- -------------  -------------------
<S>                      <C>                                                <C>                         <C>       <C>

Walter L. Armstrong       Executive Vice President, Business                 17,000** / ***              13,900     3,100** / ***
                          Development, of the Bank; Director of the
                          Company and of the Bank

John P. Clancy, Jr.       Treasurer of the Company; Senior Vice                  8,700**                  7,500        1,200**
                          President, Chief Financial Officer, Treasurer
                          and Chief Investment Officer of the Bank
                          since December 1996, and prior thereto,
                          Senior Vice President, Chief Financial
                          Officer and Treasurer of the Bank

George L. Duncan          Chairman of the Board of Directors and             149,379(9.45%)              36,300    113,079(7.16%)
                          Chief Executive Officer of the Company and
                          of the Bank

Robert R. Gilman          Executive Vice President, Administration,              9,500**                  8,000        1,500**
                          and Commercial Lender of the Bank since
                          December 1996, and prior thereto, Senior
                          Vice President, Administration, and
                          Commercial Lender of the Bank

Richard W. Main           President of the Company and President,            31,450(1.99)***             18,150    13,300** / ***
                          Chief Operating Officer and Chief Lending
                          Officer of the Bank; Director of the
                          Company and the Bank
---------
<FN>
*     =  For  purposes of this table,  the number of shares  owned prior to this  registration  includes  all
         shares which would be owned if all options granted under the Plan were exercised.                

**   =   Less than one percent.

***  =   These figures do not include shares subject to options granted to each of Mr. Armstrong and Mr. Main
         by Mr. Duncan.  Each of Mr.  Armstrong and Mr. Main has an option to purchase up to 25,000 shares of
         Common Stock  presently  held by Mr.  Duncan.  For purposes of this table,  these 50,000  shares are
         included in the shares owned by Mr. Duncan prior to and following completion of this Offering.      
</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 Nasdaq Stock Market or on a stock  exchange or other market
system if and to the extent  that the Shares are listed or  otherwise  qualified
for trading thereon 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 Common Stock is not
presently  listed or otherwise  qualified for trading on the Nasdaq Stock Market
or on any stock exchange or other market system.  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 then  prevailing  market  prices,  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 and employee 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,  officer or employee of the Company or any  affiliate of the Company
or any other  entity at the  request  or  direction  of the  Company's  Board of
Directors,  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

                                        6
<PAGE>
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 has 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 Commission 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  Organization  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  balance sheets of the Company as of December 31, 1997 and
1996 and the related consolidated statements of income, changes in stockholders'
equity  and cash  flows for each of the  years in the  three-year  period  ended
December 31, 1997 included in the Company's Annual Report on Form 10-KSB for the
year  ended  December  31,  1997 have been  audited  by KPMG Peat  Marwick  LLP,
independent  accountants,  as set forth in their report contained therein.  Such
financial  statements are  incorporated by reference in this Prospectus upon the
authority of such firm 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) of the Securities and Exchange  Commission  (the
"Commission"). In accordance with the Note to Part I of Form S-8, such documents
are not filed with 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 the Prospectus  which forms a part of
this Registration Statement:

     (a) The Company's  Registration Statement on Form 8-A, dated July 16, 1996,
relating to the Common Stock.

     (b) The Company's Annual Report on Form 10-KSB, for the year ended December
31, 1997.

     All documents filed by the Company  pursuant to Sections  13(a),  13(c), or
15(d) of the Exchange Act after the date of the Prospectus which forms a part of
this  Registration  Statement  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
such  Prospectus  and to be a part  thereof  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 such
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 and employee 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,  officer or employee of the Company or any  affiliate of the Company
or any other  entity at the  request  or  direction  of the  Company's  Board of
Directors,  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 has 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 Commission 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  Organization  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 KPMG Peat Marwick LLP

23.2     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;

     (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

                                      II-2
<PAGE>

     (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 Lowell, Commonwealth of Massachusetts, on the 6th day
of May, 1998.

                                       ENTERPRISE BANCORP, INC.


                                       By: /s/ George L. Duncan
                                          George L. Duncan
                                          Chairman and Chief Executive Officer

     The undersigned  Officers and Directors of Enterprise Bancorp,  Inc. hereby
severally  constitute  George L. Duncan,  Richard W. Main,  Arnold S. Lerner and
John P.  Clancy,  Jr.,  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/ George L. Duncan                                Chairman of the Board of Directors and Chief
George L. Duncan                                    Executive Officer                                      May 6, 1998


/s/ John P. Clancy, Jr.
John P. Clancy, Jr.                                 Treasurer (principal financial officer)                May 6, 1998


/s/ Kenneth S. Ansin 
Kenneth S. Ansin                                    Director                                               May 6, 1998


/s/ Walter L. Armstrong
Walter L. Armstrong                                 Director                                               May 6, 1998


/s/ Gerald G. Bousquet, M.D.
Gerald G. Bousquet, M.D.                            Director                                               May 6, 1998


/s/ Kathleen M. Bradley
Kathleen M. Bradley                                 Director                                               May 6, 1998


                                      II-4

<PAGE>





/s/ James F. Conway III
James F. Conway III                                 Director                                               May 6, 1998


/s/ Nancy L. Donahue 
Nancy L. Donahue                                    Director                                               May 6, 1998


/s/ Lucy A. Flynn
Lucy A. Flynn                                       Director                                               May 6, 1998


/s/ Eric W. Hanson
Eric W. Hanson                                      Director                                               May 6, 1998


/s/ John P. Harrington
John P. Harrington                                  Director                                               May 6, 1998


/s/ Arnold S. Lerner
Arnold S. Lerner                                    Director                                               May 6, 1998


/s/ Richard W. Main
Richard W. Main                                     Director                                               May 6, 1998


/s/ Charles P. Sarantos
Charles P. Sarantos                                 Director                                               May 6, 1998

/s/ Michael A. Spinelli
Michael A. Spinelli                                 Director                                               May 6, 1998


</TABLE>


                                      II-5
[{"type": "S-8", "sequence": "1", "secsgml_size_bytes": 44618}]
{"company-data": {"conformed-name": "ENTERPRISE BANCORP INC /MA/", "cik": "0001018399", "assigned-sic": "6022", "state-of-incorporation": "MA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-51953", "film-number": "98611678"}, "business-address": {"street1": "222 MERRIMACK ST", "city": "LOWELL", "state": "MA", "zip": "01852", "phone": "5084599000"}}
As filed with the Securities and Exchange Commission on May 6, 1998
                                                   Registration No. 333-

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

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

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

        Massachusetts                                 04-3308902
(State or other jurisdiction of         (I.R.S. Employer  Identification No.)
incorporation or organization)

                              222 Merrimack Street
                           Lowell, Massachusetts 01852
                    (Address of Principal Executive Offices)

                 Enterprise Bancorp, Inc. 1988 Stock Option Plan
               Enterprise Bancorp, Inc. 1998 Stock Incentive Plan
                            (Full Title of the Plans)

                               JOHN P. CLANCY, JR.
                                    Treasurer
                            Enterprise Bancorp, Inc.
                              222 Merrimack Street
                           Lowell, Massachusetts 01852
                     (Name and Address of Agent For Service)

                                 (978) 459-9000
          (Telephone number, including area code, of agent for service)

                                    Copy to:
                             STEPHEN J. COUKOS, 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                    227,287 (1)         $11.00 to $18.00 (2)     $3,180,263.50 (2)          $938.18
(1) Consists of 148,477 shares that remain authorized for issuance under the 1988 Stock Option Plan and 78,810 shares authorized for
issuance under the 1998 Stock Incentive Plan. 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 148,375 shares subject
to options currently outstanding and, for the remainder of the shares, the book value of the Common Stock as of March 31, 1998.
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 the  Company's  Common  Stock  that may be issued  upon
exercise of options  granted to certain  executive  officers under the Company's
1988 Stock Option Plan as well as shares of the Company's  Common Stock that may
be issued  either  directly  or upon  exercise  of  options  granted  to certain
executive officers and directors under the Company's 1998 Stock Incentive Plan.

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

                                  83,850 Shares
                            -------------------------

                            ENTERPRISE 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  Enterprise
Bancorp,  Inc. (the "Company"),  of up to 83,850 shares (the "Shares") of common
stock, par value $.01 per share (the "Common Stock"), of the Company,  which may
be acquired by certain executive  officers pursuant to their exercise of options
granted by the Company under the Enterprise Bancorp, Inc. 1988 Stock Option Plan
(the "Plan").  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 Nasdaq Stock Market, a stock exchange or other market system, if and
to the extent that the Common  Stock is then listed or otherwise  qualified  for
trading thereon,  at prices and on 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 not presently listed or otherwise qualified for trading
on the Nasdaq Stock Market, any stock exchange or any other market system.

  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 May 6, 1998.
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

Risk Factors .....................................................     4

Selling Shareholders .............................................     5

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 July 16, 1996,
relating to the Common Stock.

     (b) The Company's Annual Report on Form 10-KSB, for the year ended December
31, 1997.

     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 John P.  Clancy,  Jr.,  Treasurer,  Enterprise  Bancorp,  Inc.,  222
Merrimack Street, Lowell, Massachusetts 01852, telephone (978) 459-9000.

                                        3
THE COMPANY

General

     The  Company  is a  business  corporation  organized  under the laws of the
Commonwealth  of  Massachusetts  on February  29,  1996.  The only office of the
Company,  and its principal place of business,  is located at the main office of
Enterprise Bank and Trust Company (the "Bank") at 222 Merrimack Street,  Lowell,
Massachusetts 01852 and its telephone number is (978) 459-9000.

     The  Company was  organized  for the sole  purpose of becoming  the holding
company of the Bank. Upon  completion of the holding  company  formation on July
26,  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  trust  company,  which  commenced
business on January 3, 1989, and is headquartered in Lowell, Massachusetts.  The
Bank offers a range of  commercial,  consumer and trust  services with a goal of
satisfying  the  needs of  consumers,  small  and  medium-sized  businesses  and
professionals. The Bank conducts its business from its main office in Lowell and
from a network of 5  additional  branches in the  Massachusetts  communities  of
Chelmsford, Billerica, Leominster, Tewksbury and Dracut.

     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 or otherwise  permissible  nonbanking  activities.  There are no
current agreements or understandings with respect to any such acquisition and no
assurance can be given that any such future acquisitions will occur.

Property

     The  Company  neither  owns nor leases any real or personal  property.  The
Company  utilizes  the  premises,  equipment  and  furniture of the Bank on a de
minimis basis 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. The Bank
faces strong  competition  to attract  deposits and to generate  loans.  Several
major commercial banks are  headquartered  in neighboring  Boston,  and numerous
other commercial  banks,  savings banks,  cooperative  banks,  credit unions and
savings and loan  associations have one or more offices in Greater Lowell and in
the  Leominster/Fitchburg,  Massachusetts  area. The major commercial banks have
several  competitive  advantages  over the Bank,  including  the ability to make
larger loans to a single  borrower  than is possible  for the Bank.  The greater
financial  resources  of these  banks also allows them to offer a broad range of
automated  banking  services,  to maintain  numerous branch offices and to mount
extensive  advertising  and  promotional  campaigns.  Competition  for loans and
deposits  also comes from other  businesses  which provide  financial  services,
including  consumer finance  companies,  factors,  mortgage  brokers,  insurance
companies,  securities  brokerage  firms,  money market mutual funds and private
lenders.  Notwithstanding the substantial  competition facing the Bank, however,
management  believes  that the Bank has  established  a market  niche in Greater
Lowell and the Leominster/Fitchburg area which has been enhanced in recent years
by the acquisition of other independent  banks by major bank holding  companies,
and the resultant  consolidation of competitors' banking operations and services
within the Bank's market area.

Employees

     At the present  time,  the Company  does not employ any persons  other than
through the Bank.  The Company  utilizes the support staff of the Bank from time
to time without the payment of any fees, except as may be otherwise  required by
law. If the Company acquires other financial institutions or pursues other lines
of business, it may at such time hire additional employees.

                                  RISK FACTORS

     No Assurance of Public  Trading  Market.  The Common Stock is not listed or
otherwise  qualified for trading on the Nasdaq Stock Market,  any stock exchange
or any other  market  system.  No assurance  can be given that a public  trading
market for the

                                        4
Common  Stock will  develop in the  future.  Consequently,  any  purchase of the
Shares may constitute a long-term, illiquid investment.

                              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 predecessors 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
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
                                                                                                    of Shares         Following
                                                                           Shares Owned Prior         to be         Completion of
Name                      Position with Company                             to This Offering*        Offered         Offering *
------------------------  --------------------------------------------- ------------------------- -------------  -------------------
Walter L. Armstrong       Executive Vice President, Business                 17,000** / ***              13,900     3,100** / ***
                          Development, of the Bank; Director of the
                          Company and of the Bank

John P. Clancy, Jr.       Treasurer of the Company; Senior Vice                  8,700**                  7,500        1,200**
                          President, Chief Financial Officer, Treasurer
                          and Chief Investment Officer of the Bank
                          since December 1996, and prior thereto,
                          Senior Vice President, Chief Financial
                          Officer and Treasurer of the Bank

George L. Duncan          Chairman of the Board of Directors and             149,379(9.45%)              36,300    113,079(7.16%)
                          Chief Executive Officer of the Company and
                          of the Bank

Robert R. Gilman          Executive Vice President, Administration,              9,500**                  8,000        1,500**
                          and Commercial Lender of the Bank since
                          December 1996, and prior thereto, Senior
                          Vice President, Administration, and
                          Commercial Lender of the Bank

Richard W. Main           President of the Company and President,            31,450(1.99)***             18,150    13,300** / ***
                          Chief Operating Officer and Chief Lending
                          Officer of the Bank; Director of the
                          Company and the Bank
---------
*     =  For  purposes of this table,  the number of shares  owned prior to this  registration  includes  all
         shares which would be owned if all options granted under the Plan were exercised.                

**   =   Less than one percent.

***  =   These figures do not include shares subject to options granted to each of Mr. Armstrong and Mr. Main
         by Mr. Duncan.  Each of Mr.  Armstrong and Mr. Main has an option to purchase up to 25,000 shares of
         Common Stock  presently  held by Mr.  Duncan.  For purposes of this table,  these 50,000  shares are
         included in the shares owned by Mr. Duncan prior to and following completion of this Offering.
5
PLAN OF DISTRIBUTION

     The sales of the Shares by the Selling  Shareholders may be effected,  from
time to time, on the Nasdaq Stock Market or on a stock  exchange or other market
system if and to the extent  that the Shares are listed or  otherwise  qualified
for trading thereon 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 Common Stock is not
presently  listed or otherwise  qualified for trading on the Nasdaq Stock Market
or on any stock exchange or other market system.  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 then  prevailing  market  prices,  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 and employee 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,  officer or employee of the Company or any  affiliate of the Company
or any other  entity at the  request  or  direction  of the  Company's  Board of
Directors,  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

                                        6
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 has 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 Commission 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  Organization  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  balance sheets of the Company as of December 31, 1997 and
1996 and the related consolidated statements of income, changes in stockholders'
equity  and cash  flows for each of the  years in the  three-year  period  ended
December 31, 1997 included in the Company's Annual Report on Form 10-KSB for the
year  ended  December  31,  1997 have been  audited  by KPMG Peat  Marwick  LLP,
independent  accountants,  as set forth in their report contained therein.  Such
financial  statements are  incorporated by reference in this Prospectus upon the
authority of such firm 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) of the Securities and Exchange  Commission  (the
"Commission"). In accordance with the Note to Part I of Form S-8, such documents
are not filed with 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 the Prospectus  which forms a part of
this Registration Statement:

     (a) The Company's  Registration Statement on Form 8-A, dated July 16, 1996,
relating to the Common Stock.

     (b) The Company's Annual Report on Form 10-KSB, for the year ended December
31, 1997.

     All documents filed by the Company  pursuant to Sections  13(a),  13(c), or
15(d) of the Exchange Act after the date of the Prospectus which forms a part of
this  Registration  Statement  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
such  Prospectus  and to be a part  thereof  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 such
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 and employee 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,  officer or employee of the Company or any  affiliate of the Company
or any other  entity at the  request  or  direction  of the  Company's  Board of
Directors,  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 has 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 Commission 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  Organization  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 KPMG Peat Marwick LLP

23.2     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;

     (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

                                      II-2
(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 Lowell, Commonwealth of Massachusetts, on the 6th day
of May, 1998.

                                       ENTERPRISE BANCORP, INC.

                                       By: /s/ George L. Duncan
                                          George L. Duncan
                                          Chairman and Chief Executive Officer

     The undersigned  Officers and Directors of Enterprise Bancorp,  Inc. hereby
severally  constitute  George L. Duncan,  Richard W. Main,  Arnold S. Lerner and
John P.  Clancy,  Jr.,  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/ George L. Duncan                                Chairman of the Board of Directors and Chief
George L. Duncan                                    Executive Officer                                      May 6, 1998

/s/ John P. Clancy, Jr.
John P. Clancy, Jr.                                 Treasurer (principal financial officer)                May 6, 1998

/s/ Kenneth S. Ansin 
Kenneth S. Ansin                                    Director                                               May 6, 1998

/s/ Walter L. Armstrong
Walter L. Armstrong                                 Director                                               May 6, 1998

/s/ Gerald G. Bousquet, M.D.
Gerald G. Bousquet, M.D.                            Director                                               May 6, 1998

/s/ Kathleen M. Bradley
Kathleen M. Bradley                                 Director                                               May 6, 1998

                                      II-4
/s/ James F. Conway III
James F. Conway III                                 Director                                               May 6, 1998

/s/ Nancy L. Donahue 
Nancy L. Donahue                                    Director                                               May 6, 1998

/s/ Lucy A. Flynn
Lucy A. Flynn                                       Director                                               May 6, 1998

/s/ Eric W. Hanson
Eric W. Hanson                                      Director                                               May 6, 1998

/s/ John P. Harrington
John P. Harrington                                  Director                                               May 6, 1998

/s/ Arnold S. Lerner
Arnold S. Lerner                                    Director                                               May 6, 1998

/s/ Richard W. Main
Richard W. Main                                     Director                                               May 6, 1998

/s/ Charles P. Sarantos
Charles P. Sarantos                                 Director                                               May 6, 1998

/s/ Michael A. Spinelli
Michael A. Spinelli                                 Director                                               May 6, 1998
II-5