EXHIBIT 99
                                                                      ----------



Dear Shareholder:

Enterprise  Bancorp,  Inc. reported  year-to-date net income of $3.5 million for
the six months ended June 30, 2004 compared to $3.2 million for the 2003 period.
The  increase  was due  primarily  to lower tax  expense  in  2004(1)  which was
partially  offset by  declines  in net  gains  realized  on sales of  investment
securities and residential  mortgage loans, and an increase in the first quarter
provision  for loan  losses  compared to 2003.  Net income for the three  months
ended June 30, 2004 amounted to $1.7  million,  compared to $2.7 million for the
same period in 2003.  The primary  factors  contributing  to the decrease in net
income,  as compared to the second  quarter of 2003, was the reversal in 2003 of
$0.8 million of tax provisions(1)  reducing tax expense for that period, as well
as a decline in net gains realized on sales of investment  securities during the
2004 quarter.

This quarter  marked yet another  milestone for  Enterprise  Bancorp,  Inc. when
total  assets  surpassed  the $800 million  mark!  At June 30, 2004 total assets
amounted to $809.8  million,  an increase of 8% from June 30, 2003.  Total loans
were $531.2  million at June 30,  2004,  an increase of 19% over the prior year.
Deposits plus repurchase  agreements grew to $738.3 million at June 30, 2004, an
increase of 9% over June 30, 2003. In addition,  the  Investment  Management and
Trust Group reported investment assets under management of $394.6 million, a 12%
increase versus one year ago. Total assets,  investment assets under management,
and  mortgage  loans  serviced  for others  amounted to $1.2 billion at June 30,
2004, an increase of 9% from June 30, 2003.

As first  reported to you at March 31, our new branch  office at 63 Park Street,
Andover,  has been very well  received by the  community.  Our  Andover  team is
aggressively calling on potential customers  throughout Andover,  North Andover,
Lawrence,  Methuen  and Salem,  New  Hampshire.  We  continually  hear about the
tremendous  need in the market,  due to mergers and  acquisitions,  for a strong
commercial  bank  with  deep  roots  in the  community.  Our  seasoned  team  of
well-known banking professionals,  equipped with highly-competitive products and
personalized service, is creating strong business relationships for our bank. On
June 10, the bank  hosted a "Thank You  Andover"  reception  at Old Town Hall in
Andover,  which attracted a large number of business  owners and  professionals.
Enterprise's  potential in Andover is tremendous,  and we look forward to moving
to our permanent  location at 8 High Street,  once extensive  renovations to the
existing facility have been completed in the Spring of 2005.

Construction  began recently on the new commercial  building at 1120 Main Street
that will become the home of our second branch  office in Tewksbury.  As tenants
in the building,  we expect to start our leasehold  improvements within the next
few months. Tewksbury Center has attracted many thriving businesses,  and we are
looking forward to opening our new office in Tewksbury's  commercial  center. We
anticipate moving into the new building during the first quarter of 2005.

Reflecting  extensive  comparative product research conducted earlier this year,
in May,  the bank  recently  introduced  a new line of  highly  competitive  and
creative business products.  We feel these new products will serve as additional
tools to  attract  commercial  relationships.  Senior  management  is  currently
reviewing our retail  product  offerings,  and we anticipate  that a new line of
personal products will be rolled out during the next several months.

Our Investment Management and Trust Group reports strong growth in the brokerage
and  investment  management  areas.  Many new  client  relationships  have  been
established  in 2004.  To further  assist our  investment  clients,  in May,  we
welcomed Vice  President  Daniel Burke to our  investment  team. Dan brings over
sixteen  years of experience in the  financial  services,  investment  and legal
professions. A graduate of Boston College, Boston College Law School, and Babson
College, MBA program, Dan was previously  associated with both Oppenheimer Funds
Inc. in Boston, and The Collaborative Wealth Advisors Inc. in Westford.

Since its inception,  Enterprise Bank has been a strong advocate of the arts and
cultural  activities in the  communities we serve.  We are proud to include many
such organizations as our customers and friends.  We are delighted that downtown
Lowell has been  recently  recognized in the media  throughout  New England as a
true center of artistic  endeavors.  The  creation  of the  artists  lofts,  the
vibrant  museum  community,  and the increased  support of cultural and artistic
activity overall,  bodes well for the city's vibrant future.  When you visit our
main office on  Merrimack  Street,  take a moment to pause and enjoy the work of
very talented young artists that collaborated in creating a 30-foot mural on the
outer wall of the adjacent parking lot.  Spearheaded by The Revolving  Museum, a
neighboring  artistic  organization,  the mural is a testament to the talent and
ingenuity of local students.

We are pleased to share news about two highly-respected  directors of Enterprise
Bank.  Director  James F.  Conway  III,  was  recently  named the  President  of
Associated Industries of Massachusetts  (A.I.M.), in addition to his position as
President & CEO of Courier Corporation.  With its strong commitment to improving
the region's  business  economy,  A.I.M. is considered the premiere voice of the
business  community in the Commonwealth,  representing over 7,600 employers from
all industries on legislative and regulatory issues in Boston and Washington. In
addition, Director Nickolas Stavropoulos,  formerly EVP of KeySpan and President
of KeySpan  Energy  Delivery New England,  has recently been named  President of
KeySpan  Energy  Delivery  and  assumed  additional   responsibilities  for  the
company's  New  York  and  Long  Island  regions.  We are  proud  to  have  such
distinguished business leaders on our Bank's Board of Directors.

The  Board  of  Directors  joins  us in  expressing  our  appreciation  to those
shareholders  who participated in our 2004 annual meeting on May 4. Your loyalty
and support are key components in the bank's overall success.


Sincerely,



/s/ George L. Duncan      /s/ Richard W. Main          /s/ John P. Clancy, Jr.
- ----------------------    -------------------------    ------------------------
George L. Duncan          Richard W. Main              John P. Clancy, Jr.
Chairman/Chief            President/Chief Lending      President/Enterprise
Executive Officer         Officer/Chief Operating      Bancorp Inc./EVP/
                          Officer                      Treasurer/Enterprise Bank


(1) In March 2003,  the company  provided for $1.9 million in state tax expenses
due to  retroactive  assessments  related to changes in  Massachusetts  tax laws
concerning the company's REIT subsidiary. In June 2003, the company subsequently
reversed  $0.8  million  of the March tax  expense.  The  reversal  was due to a
settlement  agreement  between  the  Massachusetts  Department  of  Revenue  and
Enterprise Bank, along with approximately  sixty-five other Massachusetts banks,
regarding  disputed  retroactive  assessments  for 1999 through 2002.  Under the
terms of the settlement,  the net tax expense recorded in 2003 was approximately
$1.1 million.










                    Enterprise Bancorp, Inc. and Subsidiaries

                              STATEMENTS OF INCOME
                                   (unaudited)



                                                            Three Months Ended June 30,       Six Months Ended June 30,
                                                                                          -----------------------------
                                                               2004            2003           2004             2003
                                                          ------------    ------------    ------------    -------------
                                                                                              
INTEREST AND DIVIDEND INCOME
    Loans                                                 $  7,625,520    $  7,031,103    $ 15,184,851    $ 13,920,825
    Investment securities                                    1,757,756       2,056,734       3,481,543       4,558,330
    Short term investments                                      70,759          63,595          85,117          87,615
                                                          ------------    ------------    ------------    ------------
       Total interest and dividend income                    9,454,035       9,151,432      18,751,511      18,566,770
                                                          ------------    ------------    ------------    ------------

INTEREST EXPENSE
                                                                                                             3,571,261
    Deposits                                                 1,520,486       1,718,854       2,976,475
    Repurchase agreements                                       15,450           3,142          25,991           6,068
    Federal Home Loan Bank borrowings                           11,530          23,036          68,183          45,635
    Junior subordinated debentures                             294,305         294,305         588,610         588,610
                                                          ------------    ------------    ------------    ------------
       Total interest expense                                1,841,771       2,039,337       3,659,259       4,211,574
                                                          ------------    ------------    ------------    ------------

NET INTEREST INCOME                                          7,612,264       7,112,095      15,092,252      14,355,196

    Provision for loan losses                                  300,000         300,000       1,050,000         600,000
                                                          ------------    ------------    ------------    ------------

    Net interest income after provision for loan losses      7,312,264       6,812,095      14,042,252      13,755,196

    Non-interest income                                      1,578,794       1,688,231       3,127,970       3,276,929
    Net gains on sales of investment securities                  9,561         239,141         640,478       1,554,895
    Operating expenses                                      (6,174,862)     (5,782,397)    (12,373,952)    (11,665,004)
                                                          ------------    ------------    ------------    ------------

    Income before provision for income taxes                 2,725,757       2,957,070       5,436,748       6,922,016

    Provision for income taxes                                 981,725         259,558       1,977,470       3,720,430
                                                          ------------    ------------    ------------    ------------

NET INCOME                                                $  1,744,032    $  2,697,512    $  3,459,278    $  3,201,586
                                                          ============    ============    ============    ============
EARNINGS PER SHARE
Basic earnings per common share                           $       0.48    $       0.76    $       0.96    $       0.90
                                                          ============    ============    ============    ============
Diluted earnings per common share                         $       0.46    $       0.73    $       0.91    $       0.87
                                                          ============    ============    ============    ============
Dividend per common share (1)                             $       0.43    $       0.38    $       0.43    $       0.38
                                                          ============    ============    ============    ============
Basic weighted average common shares outstanding (2)         3,625,914       3,544,125       3,615,629       3,538,836
                                                          ============    ============    ============    ============
Diluted weighted average common shares outstanding           3,779,147       3,678,677       3,784,413       3,669,796
                                                          ============    ============    ============    ============



(1)  Annual  dividends  are  generally  declared  in the second  quarter of each
     fiscal year.

(2)  Weighted  average  common  shares  outstanding  have  increased  due to the
     exercise of employee stock options and  reinvestment  of dividends from the
     dividend reinvestment plan.







                    Enterprise Bancorp, Inc. and Subsidiaries

                                 BALANCE SHEETS
                                   (unaudited)




                                                        June 30, 2004     December 31, 2003    June 30, 2003
                                                      -----------------   -----------------  ---------------
                                                                                    
ASSETS
    Cash and due from banks                            $    36,575,260    $    31,101,961    $    41,070,108
    Short term investments                                  33,000,000         14,000,000         66,065,000
    Investment securities                                  188,172,683        196,308,098        178,612,572
    Loans                                                  531,191,136        488,839,152        444,584,295
       Allowance for loan losses                           (10,413,665)        (9,986,425)       (10,047,877)
                                                       ---------------    ---------------    ---------------
       Net loans                                           520,777,471        478,852,727        434,536,418
                                                       ---------------    ---------------    ---------------
    Bank premises and equipment                             12,035,588         12,429,021         13,153,483
    Intangible assets                                        6,463,738          6,530,123          6,596,508
    Other assets                                            12,769,967         12,323,241         12,051,977
                                                       ---------------    ---------------    ---------------

TOTAL ASSETS                                           $   809,794,707    $   751,545,171    $   752,086,066
                                                       ===============    ===============    ===============

LIABILITIES AND STOCKHOLDERS' EQUITY
    Deposits                                           $   735,475,915    $   660,824,382    $   679,131,062
    Repurchase agreements                                    2,875,282            953,924            952,965
    Federal Home Loan Bank borrowings                        1,932,500         20,470,000          5,470,000
    Junior subordinated debentures                          10,825,000         10,825,000         10,825,000
    Other liabilities                                        2,920,171          3,721,291          4,068,600
                                                       ---------------    ---------------    ---------------
       Total liabilities                                   754,028,868        696,794,597        700,447,627
                                                       ---------------    ---------------    ---------------

    Stockholders' equity                                    55,708,391         52,511,133         48,563,183
    Net unrealized appreciation on investment
       securities, net of taxes                                 57,448          2,239,441          3,075,256
                                                       ---------------    ---------------    ---------------
       Total stockholders' equity                           55,765,839         54,750,574         51,638,439
                                                       ---------------    ---------------    ---------------

 TOTAL LIABILITIES &  STOCKHOLDERS' EQUITY             $   809,794,707    $   751,545,171    $   752,086,066
                                                       ===============    ===============    ===============


    Investment assets under management                 $   394,551,585    $   375,296,992    $   352,815,990
                                                       ===============    ===============    ===============

    Mortgage loans serviced for others                 $    14,475,526    $    15,077,295    $    16,556,486
                                                       ===============    ===============    ===============

    Total assets, investment assets under management
      and mortgage loans serviced for others           $ 1,218,821,818    $ 1,141,919,458    $ 1,121,458,542
                                                       ===============    ===============    ===============