1
                       SECURITIES AND EXCHANGE COMMISSION

                              WASHINGTON, DC 20549

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

                                    FORM 8-K



                                 CURRENT REPORT



                     PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934




Date of Report (Date of Earliest Event Reported):                April 9, 1998


                     American Science and Engineering, Inc.
             (Exact Name of Registrant as Specified in Its Charter)



                                                                               
            Massachusetts                             1-6549                               04-2240991
   (State or Other Jurisdiction of           (Commission File Number)         (I.R.S. Employer Identification No.)
            Incorporation)



         829 Middlesex Turnpike, Billerica, MA                       01821
        (Address of Principal Executive Offices)                   (Zip Code)




                                 (978) 262-8700
              (Registrant's Telephone Number, Including Area Code)
   2
Item 5.       Other Events.

         On April 9, 1998, the Board of Directors of American Science and
Engineering, Inc. (the "Company") declared a dividend of one preferred share
purchase right (a "Right") for each outstanding share of common stock, par value
$0.66 2/3 per share (the "Common Shares"), of the Company. The dividend is
payable on April 17, 1998 to all holders of record of Common Shares as of the
close of business on April 17, 1998 (the "Record Date"). Each Right entitles the
registered holder to purchase from the Company one one-thousandth of a share of
Series A Junior Participating Preferred Stock, no par value (the "Preferred
Shares"), of the Company at a price of $60.00 per one one-thousandth of a
Preferred Share (the "Purchase Price"), subject to adjustment.

         The description and terms of the Rights are set forth in a Rights
Agreement (the "Rights Agreement") between the Company and American Stock
Transfer & Trust Co., New York, New York, as Rights Agent (the "Rights Agent").
A copy of the Rights Agreement is attached hereto as an exhibit and is hereby
incorporated by reference. The following summary of the Rights is qualified in
its entirety by reference to the Rights Agreement.

         Until the earliest to occur of (i) 10 business days following a public
announcement that a person or group of affiliated or associated persons (an
"Acquiring Person") has acquired beneficial ownership of 15% or more of the
outstanding Common Shares or (ii) 10 business days (or such other date as may be
determined by the Board of Directors) following the commencement of a tender
offer or exchange offer the consummation of which would result in the beneficial
ownership by a person or group of 15% or more of the outstanding Common Shares,
or (iii) the date on which the Board of Directors determines that a person or
group which beneficially owns more than 10% of the outstanding Common Shares is
an Adverse Person, as defined in the Rights Agreement (the earliest of such
dates being called the "Distribution Date"), the Rights will be evidenced by the
certificates representing Common Shares.

         The Rights Agreement provides that, until the Distribution Date (or
earlier redemption or expiration of the Rights), the Rights will be transferred
with and only with the Common Shares. Until the Distribution Date (or earlier
redemption or expiration of the Rights), certificates representing Common Shares
issued after the Record Date upon transfer or new issuance will contain a
notation incorporating the Rights Agreement by reference. Until the Distribution
Date (or earlier redemption or expiration of the Rights), the surrender for
transfer of any certificates for Common Shares outstanding as of the Record
Date, even without such notation, will also constitute the transfer of the
Rights associated with the Common Shares represented by such certificate.

         As soon as practicable following the Distribution Date, separate
certificates evidencing the Rights ("Right Certificates") will be mailed to
holders of record of the Common Shares as of the close of business on the
Distribution Date, and thereafter such separate Right Certificates alone will
evidence the Rights.

         The Rights are not exercisable until the Distribution Date. The Rights
will expire on April 16, 2008 (the "Final Expiration Date"), unless the Final
Expiration Date is extended or unless the Rights are earlier redeemed or
exchanged by the Company, in each case, as described below.


                                      -2-
   3
         At any time following the Distribution Date, Rights (other than Rights
owned by an Acquiring Person or Adverse Person, and the Acquiring Person's or
Adverse Person's affiliates and associates, which will have become void) may be
exercised (subject to their earlier termination, expiration or exchange) to
acquire that number of Preferred Shares at the then current Purchase Price of
the Right, or if the Board of Directors so determines, Common Shares, which at
such time will have a market value of two times the Purchase Price of the Right.

         The Purchase Price payable, and the number of Preferred Shares or other
securities or property issuable, upon exercise of the Rights are subject to
adjustment from time to time to prevent dilution (i) in the event of a stock
dividend on, or a subdivision, combination or reclassification of, the Preferred
Shares, (ii) upon the grant to holders of the Preferred Shares of certain rights
or warrants to subscribe for or purchase Preferred Shares at a price, or
securities convertible into Preferred Shares with a conversion price, less than
the then-current market price of the Preferred Shares or (iii) upon the
distribution to holders of the Preferred Shares of evidences of indebtedness or
assets (excluding regular periodic cash dividends paid out of earnings or
retained earnings or dividends payable in Preferred Shares) or of subscription
rights or warrants (other than those referred to above).

         The number of outstanding Rights and the number of one one-thousandths
of a Preferred Share issuable upon exercise of each Right are also subject to
adjustment in the event of a stock split of the Common Shares or a stock
dividend on the Common Shares payable in Common Shares or subdivisions,
consolidations or combinations of the Common Shares occurring, in any such case,
prior to the Distribution Date.

         Preferred Shares purchasable upon exercise of the Rights will not be
redeemable. Each Preferred Share will be entitled to a minimum preferential
quarterly dividend payment of $1.00 per share but will be entitled to an
aggregate dividend of 1,000 times the dividend declared per Common Share. In the
event of liquidation, the holders of the Preferred Shares will be entitled to a
minimum preferential liquidation payment of $1,000 per share but will be
entitled to an aggregate payment of 1,000 times the payment made per Common
Share. Each Preferred Share will have 1,000 votes, voting together with the
Common Shares. Finally, in the event of any merger, consolidation or other
transaction in which Common Shares are exchanged, each Preferred Share will be
entitled to receive 1,000 times the amount received per Common Share. These
rights are protected by customary antidilution provisions.

         Because of the nature of the dividend, liquidation and voting rights of
the Preferred Shares, the value of one one-thousandth of a Preferred Share
purchasable upon exercise of each Right should approximate the value of one
Common Share.

         In the event that any person or group of affiliated or associated
persons becomes an Acquiring Person, proper provision shall be made so that each
holder of a Right, other than Rights beneficially owned by the Acquiring Person
or Adverse Person or the affiliates and associates of such Acquiring Person or
Adverse Person (which will thereafter be void), will thereafter have the right
to receive upon exercise that number of Preferred Shares having a market value
of two times the Purchase Price of the Right.


                                      -3-
   4
         At any time after any person or group becomes an Acquiring Person and
prior to the acquisition by such person or group of 50% or more of the
outstanding Common Shares, the Board of Directors of the Company may exchange
the Rights (other than Rights owned by such person or group and their respective
affiliates and associates which will have become void) in whole or in part, at
an exchange ratio of one one-thousandth of a Preferred Share (or of a share of a
class or series of the Company's Preferred Stock having equivalent rights,
preferences and privileges) or one Common Share per Right (subject to
adjustment).

         With certain exceptions, no adjustment in the Purchase Price will be
required until cumulative adjustments require an adjustment of at least 1% in
such Purchase Price. No fractional Preferred Shares will be issued (other than
fractions which are integral multiples of one one-thousandth of a Preferred
Share, which may, at the election of the Company, be evidenced by depository
receipts) and in lieu thereof, an adjustment in cash will be made based on the
market price of the Preferred Shares on the last trading day prior to the date
of exercise.

         At any time prior to or within 10 business days following (i) the
acquisition by a person or group of affiliated or associated persons of
beneficial ownership of 15% or more of the outstanding Common Shares, or (ii)
the date on which the Board of Directors of the Company determines a person or
group to be an Adverse Person, the Board of Directors of the Company may redeem
the Rights in whole, but not in part, at a price of $.01 per Right (the
"Redemption Price"). The redemption of the Rights may be made effective at such
time on such basis with such conditions as the Board of Directors in its sole
discretion may establish. Immediately upon any redemption of the Rights, the
right to exercise the Rights will terminate and the only right of the holders of
Rights will be to receive the Redemption Price.

         In the event that the Company is acquired in a merger or other business
combination transaction or 50% or more of its consolidated assets or earning
power are sold after a person or group has become an Acquiring Person, proper
provision will be made so that each holder of a Right (other than an Acquiring
Person or Adverse Person and the affiliates and associates of such Acquiring
Person or Adverse Person, whose Rights will have become void) will thereafter
have the right to receive, upon the exercise thereof at the then current
Purchase Price of the Right, that number of shares of common stock of the
acquiring company which at the time of such transaction will have a market value
of two times the Purchase Price of the Right.

         Until a Right is exercised, the holder thereof, as such, will have no
rights as a stockholder of the Company, including, without limitation, the right
to vote or to receive dividends.

         Prior to the Distribution Date, the Company may supplement or amend any
provision of the Rights Agreement in any manner. From and after the Distribution
Date, the Company may supplement or amend the Rights Agreement to: (i) cure any
ambiguity; (ii) correct or supplement any provision contained in the Rights
Agreement which may be defective or inconsistent with any other provision of the
Rights Agreement; (iii) shorten or lengthen any time period contained in the
Rights Agreement; or (iv) change or supplement the provisions in the Rights
Agreement in any manner which the Company may deem necessary or desirable and
which shall not adversely affect the interest of the holders of 


                                      -4-
   5
Rights (other than Rights owned by an Acquiring Person, Adverse Person or any
affiliate or associate of an Acquiring Person or Adverse Person).

Item 7.       Financial Statements and Exhibits.

       (a)    Financial Statements of Businesses Acquired

              Not Applicable

       (b)    Pro Forma Financial Information

              Not Applicable

       (c)    Exhibits

              4.      Shareholder Rights Agreement dated as of April 17, 1998
                      between American Science and Engineering, Inc. and
                      American Stock Transfer & Trust Co., Inc., as Rights
                      Agent, which includes as Exhibit C a summary of the
                      provisions of the Rights Agreement and as Exhibit B the
                      forms of Right Certificate and Election to Exercise.


                                      -5-
   6
                                    SIGNATURE


         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.


                                       AMERICAN SCIENCE AND ENGINEERING, INC.


                                       By: /s/ Ralph S. Sheridan
                                           ------------------------------------
                                           Name:  Ralph S. Sheridan
                                           Title: President and Chief
                                                  Executive Officer

Dated:  April 14, 1998


                                      -6-