UNITED STATES
                 SECURITIES AND EXCHANGE COMMISSION
                       Washington, D.C. 20549

                            SCHEDULE 13G

              Under the Securities Exchange Act of 1934
                             (Amendment)

NAME OF ISSUER                HARMONIC LIGHTWAVES, INC.

TITLE OF CLASS OF SECURITIES       Common

CUSIP NUMBER                  413160102


The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject
class of securities, and for any subsequent amendment containing
information which would alter the disclosures provided in a prior
cover page.

The information required in the remainder of this cover page shall
not be deemed to be "filed" for the purpose of Section 18 of the
Securities Exchange Act of 1934 ("Act") or otherwise subject to the
liabilities of that section of the Act but shall be subject to all
other provisions of the Act (however, see the Notes).
























                         Page 1 of 11 Pages

                                 13G

CUSIP No. 413160102                               Page 2 of 11 Pages
- --------------------------------------------------------------------
- ----------
1.   Name of reporting person
     S.S. or I.R.S. identification no. of above person

     Marsh & McLennan Companies, Inc.
     36-2668272
- --------------------------------------------------------------------
- ----------
2.   Check the appropriate box if a member of a group*
     (a)(   )       (b)(   )
- --------------------------------------------------------------------
- ----------
3.   SEC use only

- --------------------------------------------------------------------
- ----------
4.   Citizenship or place of organization

     Delaware
- --------------------------------------------------------------------
- ----------
                                                  5.   Sole Voting
                                   Power

                                   NONE
                              -----------------------------
Number of shares                   )    6.   Shared Voting Power
Beneficially   )
Owned by each  )              NONE
Reporting           )              -----------------------------
Person with:                       )    7.   Sole Dispositive Power

                                   NONE
                              -----------------------------
                                                  8.   Shared
                                   Dispositive Power

                                   NONE
- --------------------------------------------------------------------
- ----------
9.   Aggregate amount beneficially owned by each reporting person

     NONE
- --------------------------------------------------------------------
- ----------
10.     Check box if the aggregate amount in row (9) excludes
        certain shares*

- --------------------------------------------------------------------
- ----------
11.     Percent of class represented by amount in row 9

     NONE
- --------------------------------------------------------------------
- ----------
12.     Type of Reporting person*

     HC
- --------------------------------------------------------------------
- ----------

                                 13G
                                  
CUSIP No. 413160102                               Page 3 of 11 Pages
- --------------------------------------------------------------------
- ----------
1.   Name of reporting person
    S.S. or I.R.S. identification no. of above person

       Putnam Investments, Inc.
       04-2539558
- --------------------------------------------------------------------
- ----------
2.   Check the appropriate box if a member of a group*
          (a)(   )       (b)(   )
- --------------------------------------------------------------------
- ----------
3.      SEC use only

- --------------------------------------------------------------------
- ----------
4.      Citizenship or place of organization

          Massachusetts
- --------------------------------------------------------------------
- ----------
                                                  5.   Sole Voting
                                   Power

                                   NONE
Number of       shares   )              ----------------------------
- -
Beneficially                       )    6.   Shared Voting Power
owned by each  )
                                   306,100
Reporting           )
Person with:   )              -----------------------------
                                                  7.   Sole
                                   Dispositive Power

                                   NONE
                              -----------------------------
                                                  8.   Shared
                                   Dispositive Power

                                   1,751,678
- --------------------------------------------------------------------
- ----------
9.   Aggregate amount beneficially owned by each reporting person

               1,751,678

- --------------------------------------------------------------------
- ----------
10.     Check box if the aggregate amount in row (9) excludes
        certain shares*

- --------------------------------------------------------------------
- ----------
11.     Percent of class represented by amount in row 9

               12.7%
- --------------------------------------------------------------------
- ----------
12.     Type of Reporting person*

       HC
- --------------------------------------------------------------------
- ----------

                                 13G
                                  
CUSIP No. 413160102                               Page 4 of 11 Pages
- --------------------------------------------------------------------
- ----------
1.      Name of reporting person
        S.S. or I.R.S. identification no. of above person

        Putnam Investment Management, Inc.
       04-2471937
- --------------------------------------------------------------------
- ----------
2.      Check the appropriate box if a member of a group*
          (a)(   )       (b)(   )
- --------------------------------------------------------------------
- ----------
3.      SEC use only

- --------------------------------------------------------------------
- ----------
4.   Citizenship or place of organization

     Massachusetts
- --------------------------------------------------------------------
- ----------
                                                  5.   Sole Voting
                                   Power

                                   NONE
Number of       shares   )              ----------------------------
- -
Beneficially                       )    6.   Shared Voting Power
Owned by each  )
Reporting           )              NONE
Person with:   )              -----------------------------
                                                  7.   Sole
                                   Dispositive Power

                                   NONE
                              -----------------------------
                                             8.   Shared Dispositive
                                   Power

                                   1,334,078
- --------------------------------------------------------------------
- ----------
9.      Aggregate amount beneficially owned by each reporting person

          1,334,078
- --------------------------------------------------------------------
- ----------
10.     Check box if the aggregate amount in row (9) excludes
        certain shares*

- --------------------------------------------------------------------
- ----------
11.     Percent of class represented by amount in row 9

          9.7%
- --------------------------------------------------------------------
- ----------
12.     Type of Reporting person*

        IA
- --------------------------------------------------------------------
        ----------

                                 13G
                                  
CUSIP No. 413160102                               Page 5 of 11 Pages
- --------------------------------------------------------------------
- ----------
1.   Name of reporting person
        S.S. or I.R.S. identification no. of above person

        The Putnam Advisory Company, Inc.
        04-6187127
- --------------------------------------------------------------------
- ----------
2.      Check the appropriate box if a member of a group*
          (a)(   )       (b)(   )
- --------------------------------------------------------------------
- ----------
3.      SEC use only

- --------------------------------------------------------------------
- ----------
4.      Citizenship or place of organization

               Massachusetts
- --------------------------------------------------------------------
- ----------
                                                  5.   Sole Voting
                                   Power

                                   NONE
Number of       shares   )              ----------------------------
- -
Beneficially                       )    6.   Shared Voting Power
Owned by each  )
Reporting           )              306,100
Person with:   )              -----------------------------
                                                  7.   Sole
                                   Dispositive Power

                                   NONE
                              -----------------------------
                                                  8.   Shared
                                   Dispositive Power

                                   417,600
- --------------------------------------------------------------------
- ----------
9.   Aggregate amount beneficially owned by each reporting person

               417,600
- --------------------------------------------------------------------
- ----------
10.  Check box if the aggregate amount in row (9) excludes certain
shares*

- --------------------------------------------------------------------
- ----------
11.  Percent of class represented by amount in row 9

     3.0%
- --------------------------------------------------------------------
- ----------
12.  Type of Reporting person*

        IA
- --------------------------------------------------------------------
- ----------


                                 13G
                                  
CUSIP No. 413160102                               Page 6 of 11 Pages
- --------------------------------------------------------------------
- ----------
1.   Name of reporting person
        S.S. or I.R.S. identification no. of above person

        Putnam OTC & Emerging Growth Fund
        04-6483374
- --------------------------------------------------------------------
- ----------
2.      Check the appropriate box if a member of a group*
          (a)(   )       (b)(   )
- --------------------------------------------------------------------
- ----------
3.      SEC use only

- --------------------------------------------------------------------
- ----------
4.      Citizenship or place of organization

               Massachusetts
- --------------------------------------------------------------------
- ----------
                                                  5.   Sole Voting
                                   Power

                                   NONE
Number of       shares   )              ----------------------------
- -
Beneficially                       )    6.   Shared Voting Power
Owned by each  )
Reporting           )              NONE
Person with:   )              -----------------------------
                                                  7.   Sole
                                   Dispositive Power

                                   NONE
                              -----------------------------
                                                  8.   Shared
                                   Dispositive Power

                                   942,900
- --------------------------------------------------------------------
- ----------
9.   Aggregate amount beneficially owned by each reporting person

    942,900
- --------------------------------------------------------------------
- ----------
10.  Check box if the aggregate amount in row (9) includes certain
shares*

- --------------------------------------------------------------------
- ----------
11.  Percent of class represented by amount in row 9

       7%
- --------------------------------------------------------------------
- ----------
12.  Type of Reporting person*

     IC
- --------------------------------------------------------------------
- ----------
                 SECURITIES AND EXCHANGE COMMISSION
                      Washington, D. C.  20549
                                  
                            SCHEDULE 13G

              Under the Securities Exchange Act of 1934
                                  


Item 1(a)      Name of Issuer:          HARMONIC LIGHTWAVES, INC.

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

549 Baltic Way, Sunnyvale, CA  94089,

Item 2(a)                               Item 2(b)

Name of Person Filing:                            Address or
                                   Principal Office or, if NONE,
                                   Residence:

Putnam Investments, Inc.           One Post Office Square
     ("PI")                             Boston, Massachusetts 02109
on behalf of itself and:

*Marsh & McLennan Companies, Inc.       1166 Avenue of the Americas
    ("MMC")                             New York, NY  10036

Putnam Investment Management, Inc.      One Post Office Square
    ("PIM")                             Boston, Massachusetts 02109

The Putnam Advisory Company, Inc.       One Post Office Square
    ("PAC")                             Boston, Massachusetts 02109

**Putnam OTC & Emerging Growth Fund                    One Post
Office Square
                                   Boston, Massachusetts  02109


Item 2(c)           Citizenship:  PI, PIM and PAC are corporations
               organized under Massachusetts law.  The citizenship
               of other persons identified in Item 2(a) is
               designated as follows:

               *    Corporation - Delaware law
                              **   Voluntary association known as
                    Massachusetts business trust - Massachusetts law


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

Item 2(e)      Cusip Number:  413160102

                         Page 7 of 11 Pages


Item 3.   If this statement is filed pursuant to Rules 13d-1(b), or
          13d-2(b), check whether the person filing is a:


(a)(   )  Broker or Dealer registered under Section 15 of the Act


(b)(   )  Bank as defined in Section 3(a)(6) of the Act


(c)(   )  Insurance Company as defined in Section 3(a)(19) of the
          Act


(d)( X  ) Investment Company registered under Section 8 of the
          Investment Company Act


(e)( X )  Investment Adviser registered under Section 203 of the
          Investment Advisers Act of 1940


(f)(   )  Employee Benefit Plan, Pension Fund which is subject to
          the provisions of the Employee Retirement Income Security
          Act of 1974 or Endowment Fund; see (Section
          240.13d-1(b)(1)(ii)(F)


(g)( X )  Parent Holding Company, in accordance with Section
          240.13d-1(b)(ii)(G)


(h)(   )  Group, in accordance with Section 240.13d-1(b)(1)(ii)(H)





                            Page 8 of 11 Pages


Item 4.
Ownership.
                                                                    
                              M&MC                PIM*           PAC            PI
                              -----                    -----               ---            ----
                         (Parent holding               (Investment advisers          (Parent company
                         company to PI)           & subsidiaries of PI)         to PIM and PAC)


(a)  Amount Beneficially
     Owned:                   NONE                1,334,078 +    417,600   =    1,751,678

(b)  Percent of Class:             NONE                9.7%      +    3.0%      =    12.7%

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

(1)  sole power to vote
     or to direct the vote;
     (but see Item 7)              NONE                NONE           NONE           NONE

(2)  shared power to vote
     or to direct the vote;
     (but see Item 7)              NONE                NONE           306,100             306,100

(3)  sole power to dispose
     or to direct the
     disposition of;
     (but see Item 7)              NONE                NONE           NONE           NONE

(4)  shared power to
     dispose or to direct
     the disposition of;
     (but see Item 7)              NONE                ALL            ALL            ALL


*As part of the Putnam Family of Funds, and the 1,334,078 shares held by PIM,
Putnam OTC & Emerging Growth Fund held 7% or 942,900 shares.
                               Page 9 of 11 Pages



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

If this statement is being filed to report the fact that as
of the date thereof the reporting person has ceased to be
the beneficial owner of more than five percent of the class
of securities, check the following ( ).

Item 6.   Ownership of More than Five/Ten Percent on Behalf
of Another Person:
No persons other than the persons filing this Schedule 13G
have an economic interest in the securities reported on
which relates to more than five percent of the class of
securities.  Securities reported on this Schedule 13G as
being beneficially owned by M&MC and PI consist of
securities beneficially owned by subsidiaries of PI which
are registered investment advisers, which in turn include
securities beneficially owned by clients of such investment
advisers, which clients may include investment companies
registered under the Investment Company Act and/or employee
benefit plans, pension funds, endowment funds or other
institutional clients.

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

PI, which is a wholly-owned subsidiary of M&MC, wholly owns
two registered investment advisers:  Putnam Investment
Management, Inc., which is the investment adviser to the
Putnam family of mutual funds and The Putnam Advisory
Company, Inc., which is the investment adviser to Putnam's
institutional clients.  Both subsidiaries have dispository
power over the shares as investment managers, but each of
the mutual fund's trustees have voting power over the shares
held by each fund, and The Putnam Advisory Company, Inc. has
shared voting power over the shares held by the
institutional clients.  Pursuant to Rule 13d-4, M&MC and PI
declare that the filing of this Schedule 13G shall not be
deemed an admission by either or both of them that they are,
for the purposes of Section 13(d) or 13(g) the beneficial
owner of any securities covered by this Section 13G, and
further state that neither of them have any power to vote or
dispose of, or direct the voting or disposition of, any of
the securities covered by this Schedule 13G.

Item 8.   Identification and Classification of Members of
the Group:
          Not applicable.

Item 9.   Notice of Dissolution of Group:

          Not applicable.

Item 10.  Certification.

                     Page 10 of 11 Pages

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, 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.


After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this
statement is true, complete and correct.


PUTNAM INVESTMENTS, INC.


     /s/Andrew J. Hachey
BY:  -------------------------------------------
     Signature

     Name/Title:    Andrew J. Hachey
     Assistant Vice President and
     Regulatory Compliance Counsel

     Date:     May 4, 1999


For this and all future filings, reference is made to Power
of Attorney dated April 30, 1999, with respect to duly
authorized signatures on behalf of Marsh & McLennan
Companies, Inc., Putnam Investments, Inc., Putnam Investment
Management, Inc., The Putnam Advisory Company, Inc. and any
Putnam Fund wherever applicable.

For this and all future filings, reference is made to an
Agreement dated June 28, 1990, with respect to one filing of
Schedule 13G on behalf of said entities, pursuant to Rule
13d-1(f)(1).






                     Page 11 of 11 Pages


                      POWER OF ATTORNEY
                              
     I, the undersigned duly authorized officer of Putnam

Investments, Inc. (the "Company), hereby severally

constitute William H. Woolverton, Karen R. Kay and Andrew J.

Hachey, and each of them, to sign on behalf of the Company a

Schedule 13G under the Securities Exchange Act of 1934, as

amended, with respect to the beneficial ownership of the

equity securities of the Company, its parent corporation,

Marsh & McLennan Companies, Inc., its subsidiaries, Putnam

Investment Management, Inc., The Putnam Advisory Company,

Inc., which are registered investment advisers, and,

wherever applicable, any Putnam Fund, which are investment

companies, together with any and all amendments thereto,

hereby ratifying and confirming such signature as it may be

signed by such attorneys to such Schedule 13G and any and

all amendments thereto.

     WITNESS my hand on behalf of the Company this 29th day

of April, 1999.



                                   PUTNAM INVESTMENTS, INC.



                                   BY: /s/: William H. Woolverton
                                         William H. Woolverton
                                         Managing Director and
General Counsel