

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


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


                    Under the Securities Exchange Act of 1934

                                  SCHEDULE 13G


             INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934




                             ACT Manufacturing, Inc.
                             -----------------------
                                (Name of Issuer)



                                  Common Stock
                                  ------------
                         (Title of Class of Securities)



                                    000973107
                                    ---------
                                 (CUSIP Number)



                                January 31, 2001
      ---------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)



Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

         |X|  Rule 13d-1(b)
         |_|  Rule 13d-1(c)
         |_|  Rule 13d-1(d)


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

                                Page 1 of 6 Pages

<PAGE>

                                  SCHEDULE 13G

CUSIP No.  000973107                                           Page 2 of 6 Pages
--------------------------------------------------------------------------------

1)         NAME OF REPORTING PERSON
           S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Gilder, Gagnon, Howe & Co. LLC
           13-3174112
--------------------------------------------------------------------------------
2)         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP      (a)   |_|

                                                                 (b)   |_|
--------------------------------------------------------------------------------
3)         SEC USE ONLY

--------------------------------------------------------------------------------
4)         CITIZENSHIP OR PLACE OF ORGANIZATION

           New York
--------------------------------------------------------------------------------
           NUMBER                    5)      SOLE VOTING POWER
           OF                                15,700
           SHARES                  ---------------------------------------------
           BENEFICIALLY              6)      SHARED VOTING POWER
           OWNED BY                          None
           EACH                    ---------------------------------------------
           REPORTING                 7)      SOLE DISPOSITIVE POWER
           PERSON                            None
           WITH                    ---------------------------------------------
                                     8)      SHARED DISPOSITIVE POWER
                                             1,263,225
--------------------------------------------------------------------------------
9)         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           1,263,225
--------------------------------------------------------------------------------
10)        CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

                                                                      |-|
--------------------------------------------------------------------------------
11)        PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           7.4%
--------------------------------------------------------------------------------
12)        TYPE OF REPORTING PERSON

           BD
--------------------------------------------------------------------------------

                                       2

<PAGE>

                                  Schedule 13G

Item 1(a).        Name of Issuer:

ACT Manufacturing, Inc.

Item 1(b).        Address of Issuer's Principal Executive Offices:

2 Cabot Road
Hudson, MA 01749

Item 2(a).        Name of Person Filing:

Gilder, Gagnon, Howe & Co. LLC

Item 2(b).        Address of Principal Business Office or, if None, Residence:

1775 Broadway, 26th Floor
New York, NY  10019

Item 2(c).        Citizenship:

New York

Item 2(d).        Title of Class of Securities:

Common Stock

Item 2(e).        CUSIP Number:

000973107

Item  3.          If this statement is filed pursuant to ss.ss. 240.13d-1(b), or
240.13d-2(b) or (c), check whether the person filing is a:

                  (a) [x]  Broker or Dealer  Registered  Under Section 15 of the
                           Act (15 U.S.C. 78o)

                  (b) |_|  Bank as  defined  in  section  3(a)(6) of the Act (15
                           U.S.C. 78c)

                  (c) |_|  Insurance  Company as defined in section  3(a)(19) of
                           the Act (15 U.S.C. 78c)

                  (d) |_|  Investment  Company registered under section 8 of the
                           Investment Company Act of 1940 (15 U.S.C. 80a-8)

                  (e) |_|  Investment        Adviser        in        accordance
                           withss.240.13d-1(b)(1)(ii)(E)

                  (f) |_|  Employee benefit plan or endowment fund in accordance
                           withss.240.13d-1(b)(1)(ii)(F)

                  (g) |_|  Parent   Holding   Company  or   control   person  in
                           accordance withss.240.13d-1(b)(ii)(G)

                                       3

<PAGE>

                  (h) |_|  Savings  Association  as  defined  inss.3(b)  of  the
                           Federal Deposit Insurance Act (12 U.S.C. 1813)

                  (i) |_|  Church plan that is excluded  from the  definition of
                           an  investment   company  under  ss.3(c)(15)  of  the
                           Investment Company Act of 1940 (15 U.S.C. 80a-3)

                  (j) |_|  Group, in accordance withss.240.13d-1(b)(ii)(J)

Item 4.           Ownership.

                  (a)      Amount beneficially owned:  1,263,225

                  (b)      Percent of class:  7.4%

                  (c)      Number of shares as to which such person has:

                           (i)      Sole  power to vote or to  direct  the vote:
                                    15,700

                           (ii)     Shared  power to vote or to direct the vote:
                                    None

                           (iii)    Sole  power  to  dispose  or to  direct  the
                                    disposition of: None

                           (iv)     Shared  power to  dispose  or to direct  the
                                    disposition of: 1,263,225

                  The shares reported include  1,199,000 shares held in customer
                  accounts over which partners and/or employees of the Reporting
                  Person have  discretionary  authority  to dispose of or direct
                  the disposition of the shares,  48,525 shares held in accounts
                  owned  by the  Partners  of the  Reporting  Person  and  their
                  families,  and  15,700  shares  held  in  the  account  of the
                  profit-sharing    plan   of   the   Reporting   Person   ("the
                  Profit-Sharing Plan").

Item 5.           Ownership of Five Percent or Less of a Class.

Not applicable

Item 6.           Ownership  of More than  Five  Percent  on  Behalf of  Another
                  Person.

The owners of the  accounts  (including  the  Profit-Sharing  Plan) in which the
shares  reported on this Schedule are held have right to receive or the power to
direct the receipt of dividends  from,  or the  proceeds  from the sale of, such
securities.

Item 7.           Identification  and  Classification  of the  Subsidiary  Which
                  Acquired the Security  Being Reported on by the Parent Holding
                  Company.

Not applicable

                                       4

<PAGE>


Item 8.           Identification and Classification of Members of the Group.

Not applicable

Item 9.           Notice of Dissolution of Group.

Not applicable

Item 10.          Certification.

                  By signing  below I certify  that, to the best of my knowledge
and  belief,  the  securities  referred to above were  acquired in the  ordinary
course of business  and were not acquired for the purpose of and do not have the
effect of changing or influencing  the control of the issuer of such  securities
and were not acquired in connection  with or as a participant in any transaction
having such purposes or effect.


                                       5

<PAGE>

                                    SIGNATURE


             After  reasonable  inquiry and to the best  knowledge and belief of
the  undersigned,  the  undersigned  certifies that the information set forth in
this Statement is true, complete and correct.


                                                       February 9, 2001
                                                     --------------------------
                                                           Date


                                                       /s/ Walter Weadock
                                                     --------------------------
                                                           Signature


                                                       Walter Weadock, Member
                                                           Name/Title


                                       6


