SCHEDULE 14A

                     INFORMATION REQUIRED IN PROXY STATEMENT

                            SCHEDULE 14A INFORMATION

           Proxy Statement Pursuant to Section 14(a) of the Securities
                              Exchange Act of 1934

    Filed by the Registrant [X]
    Filed by a Party other than the Registrant [ ]

    Check the appropriate box:

    [ ] Preliminary Proxy Statement
    [ ] Definitive Proxy Statement
    [X] Definitive Additional Materials
    [ ] Soliciting Material Pursuant to Rule 14a-11(c) or Rule 14a-12

    [ ] Confidential,  for  Use  of  the Commission  Only  (as permitted by Rule
        14a-6(e)(2))


                             Watkins-Johnson Company
             ------------------------------------------------------
                (Name of Registrant as Specified In Its Charter)

   --------------------------------------------------------------------------
    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

    [X] No fee required.

    [ ] Fee computed on table below per Exchange Act Rules 14a-6(i)(4) and 0-11.

    (1) Title of each class of securities to which transaction applies:

    (2) Aggregate number of securities to which transaction applies:

    (3) Per unit  price  or  other  underlying  value  of  transaction  computed
        pursuant  to  Exchange  Act Rule 0-11 (Set forth the amount on which the
        filing fee is calculated and state how it was determined):

    (4) Proposed maximum aggregate value of transaction:

    (5) Total fee paid:

    [ ] Fee paid previously with preliminary materials.


    [ ] Check box  if any part of the fee is offset as provided by Exchange  Act
Rule  0-11(a)(2)  and identify the filing for which the  offsetting fee was paid
previously.  Identify the previous filing by registration  statement  number, or
the Form or Schedule and the date of its filing.

    (1) Amount Previously Paid:

    (2) Form, Schedule or Registration Statement No.:

    (3) Filing Party:

    (4) Date Filed:



                             WATKINS-JOHNSON COMPANY

                              3333 Hillview Avenue
                             Stanford Research Park
                           Palo Alto, California 94304

   DEAN A. WATKINS                                        W. KEITH KENNEDY, JR.
Chairman of the Board                                         President and
                                                         Chief Executive Officer

H. RICHARD JOHNSON
   Vice Chairman

                                 April 14, 1999

- --------------------------------------------------------------------------------
                    YOUR VOTE IS IMPORTANT--PLEASE ACT TODAY
                           THANK YOU FOR YOUR SUPPORT
- --------------------------------------------------------------------------------

Dear Shareowner:

         In our March 17, 1999  letter,  we invited you to attend the  Company's
Annual  Meeting of  Shareowners,  to be held at 10:00  o'clock in the morning on
Thursday,  April 29, 1999, at Hotel  Sofitel,  233 Twin Dolphin  Drive,  Redwood
City, California 94065. We hope you can come to the Annual Meeting.

         One of the  proposals  to be acted on at the 1999  Annual  Meeting is a
proposal to eliminate the  super-majority  director  voting  requirements of the
Bylaws. On the reverse side of this letter is important  additional  information
about a  commitment  the  Board  has  made  to all  shareowners  regarding  that
proposal. We encourage you to read it carefully.

         As we said in our March 17, 1999  letter,  the matters to be acted upon
at this  year's  Annual  Meeting  are  significant  and  your  participation  is
important  whether or not you can attend.  If you have not  already  completed a
proxy card,  we ask that you take the time,  immediately,  to complete  the card
enclosed with this letter and return it in the enclosed envelope.

         If you have any  questions or need  assistance  completing  your proxy,
please  call  MacKenzie  Partners,  Inc.  at (212)  929-5500  (call  collect) or
toll-free at (800) 322-2855.

                                                         Sincerely yours,

                                                         Dean A. Watkins

                                                         H. Richard Johnson

                                                         W. Keith Kennedy, Jr.




                  ADDITIONAL INFORMATION CONCERNING PROPOSAL 3

         Our Proxy Statement describes four proposals to be acted on at the 1999
Annual Meeting of Shareowners.  One of those proposals,  i.e., Proposal 3, seeks
approval of  amendments to the Bylaws that would  eliminate  the  super-majority
director  voting  requirements  of the Bylaws  applicable  to certain  specified
decisions of the Board. Detailed information regarding Proposal 3, including the
current text of the relevant provisions of the Bylaws and the changes that would
be made to those provisions by Proposal 3, is contained in our Proxy Statement.

         After we mailed our Proxy  Statement,  we became aware of some investor
concern  that  Proposal  3 would  enable  a  minority  of the  Board to make the
decisions  covered by  Proposal 3 in the name of the whole  Board.  Although  we
believe it is unlikely that a minority of the directors  would undertake to bind
the Board as to these kinds of  decisions,  the Board  agrees that this could be
the literal  consequence of Proposal 3 because the Proposal  contemplates action
by a majority of the quorum and the Bylaws provide that a majority of the entire
Board constitutes a quorum.

         To remove this  concern,  the Board has  adopted a standing  resolution
containing  its  commitment  to each of our  shareowners  that, if Proposal 3 is
approved at the 1999 Annual Meeting, none of the decisions of the Board that are
currently  subject to the 75% approval  requirement  of the Bylaws will be taken
unless a majority of the full number of directors  then in office votes in favor
of the decision.

         Under the Company's Articles of Incorporation,  the Board has the power
to  determine  the  number  of  directors  within a range of seven to  thirteen.
Currently,  the size of the Board is fixed at  eight.  Accordingly,  unless  the
Board  changed the number of directors,  this  commitment by the Board will mean
that these  particular  Board  decisions  will have to be taken by at least five
directors,  except where, for any reason, a vacancy arises on the Board; in that
case these  decisions  would have to be taken by a majority of the actual number
of directors, less than eight, then in office.

         For the reasons set forth in the Proxy  Statement,  the Board continues
to recommend  unanimously a vote "FOR" Proposal 3 and "FOR" the other  proposals
contained in the Proxy Statement.

                                       2