<PAGE>
 
                       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): September 10, 1998
                                                        ------------------


                            CABOT INDUSTRIAL TRUST
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             (Exact name of Registrant as specific in its charter)

                                   Maryland
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        (State or other jurisdiction of incorporation or organization)

                1-13829                               04-3397866
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        (Commission File Number)         (I.R.S. Employer Identification No.)

           Two Center Plaza, Suite 200, Boston, Massachusetts 02108
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              (Address of principal executive offices) (Zip Code)

                                (617) 723-0900
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             (Registrant's telephone number, including area code)


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         (Former name or former address, if changed since last report)
<PAGE>
 
ITEM 5. OTHER EVENTS

     On September 10, 1998, the Board of Trustees of Cabot Industrial Trust (the
"Company") amended the Rights Agreement dated as of June 11, 1998, between the
Company and BankBoston, N.A., as rights agent (as amended, the "Rights
Agreement"). Under the terms of the Rights Agreement, the holders of any Common
Shares are entitled to one preferred share purchase right (a "Right") for each
common share of beneficial interest, par value $0.01 per share (the "Common
Shares").  Each Right entitles the registered holder under certain circumstances
to purchase from the Company one one-hundredth of a Series A Junior
Participating Preferred Share, par value $0.01 per share (the "Participating
Preferred Shares"), of the Company at a price of $85.00 per one one-hundredth of
a Participating Preferred Share (the "Purchase Price"), subject to adjustment.
The Rights had been issued initially by dividend of the Company to shareholders
of record on July 15, 1998 (the "Record Date").

     The Rights are attached to and evidenced by certificates evidencing Common
Shares, and no separate certificates for the Rights will be distributed.  The
Rights will become exercisable and will be evidenced by separate certificates
only after the earlier to occur of (i) 10 days following a public announcement
(or such specified or unspecified later date as may be determined by the Board
of Trustees prior to the Distribution Date (as defined below)) that a person or
group of affiliated or associated persons has acquired beneficial ownership of
15% or more of the outstanding Common Shares (thereby becoming an "Acquiring
Person"), (ii) 15 business days (or such specified or unspecified later date as
may be determined by the Board of Trustees prior to the Distribution Date)
following the commencement of, or the announcement of an intention to commence,
a tender or exchange offer the consummation of which would result in the
beneficial ownership by a person or group of persons of 15% or more of the
outstanding Common Shares, or (iii) 10 business days (or such specified or
unspecified later date as may be determined by action of the Board of Trustees
prior to the Distribution Date) after the filing of any application, request or
other document with a governmental agency seeking approval of, attempting to
rebut any presumption of control upon, or indicating an intention to enter into,
any transaction or series of transactions that would result in any person
becoming the beneficial owner of 15% or more of the outstanding Common Shares
(the first of such dates to occur being referred to herein as the "Distribution
Date").  Beneficial ownership under the Rights Agreement includes beneficial
ownership as determined under Rule 13d-3 of the General Rules and Regulations
under the Securities Exchange Act of 1934.  Common Share certificates issued
upon transfer or issuance of Common Shares after the Record Date and prior to
the Distribution Date (or earlier redemption or expiration of the Rights) will
contain a notation incorporating the Rights Agreement by reference.
Notwithstanding the foregoing, certain existing investors specified in the
Rights Agreement (the "Grandfathered Persons") who may be deemed to beneficially
own 15% or more of the Common Shares as of the Record Date will not be deemed to
be Acquiring Persons unless any such Grandfathered Person becomes the beneficial
owner of an additional 1% of the outstanding Common Shares without the prior
written approval of the Company.  In addition, if the Board of Trustees in good
faith determines that a person who would otherwise be an Acquiring Person has
become such inadvertently, and such person divests as promptly as practicable a
sufficient number of Common Shares so that such person would no longer be an
Acquiring Person, then such person shall not be deemed to be an Acquiring Person
for purposes of the Rights Agreement.

                                      -1-
<PAGE>
 
     The Rights will expire on June 11, 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.

     The Purchase Price payable, and the number of Participating Preferred
Shares or other securities or property issuable, upon exercise of the Rights are
subject to adjustment under certain circumstances from time to time to prevent
dilution.  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.

     Participating Preferred Shares purchasable upon exercise of the Rights will
not be redeemable.  Each Participating Preferred Share will be entitled to a
minimum preferential quarterly distribution payment, when, as and if authorized
by the Board of Trustees out of funds legally available for such purpose, of
$1.00 per share but will be entitled to an aggregate distribution of 100 times
any distribution declared per Common Share.  In the event of liquidation, the
holders of the Participating Preferred Shares will be entitled to a minimum
preferential liquidation payment of $1.00 per share but will be entitled to an
aggregate payment of 100 times the payment made per Common Share.  Each
Participating Preferred Share will have 100 votes, voting together with the
Common Shares.  In the event of any merger, consolidation or other transaction
in which Common Shares are exchanged, each Participating Preferred Share will be
entitled to receive 100 times the amount received per Common Share.  In the
event of issuance of Participating Preferred Shares upon exercise of the Rights,
in order to facilitate trading, a depositary receipt may be issued for each one
one-hundredth of a Participating Preferred Share.  The Rights will be protected
by customary antidilution provisions.

     In the event that any person or group of affiliated or associated persons
becomes an Acquiring Person, proper provision will be made so that each holder
of a Right, other than Rights beneficially owned by the Acquiring Person (which
will thereafter be void), will thereafter have the right to receive, upon
exercise thereof, a number of Common Shares having a market value (determined in
accordance with the Rights Agreement) equal to two times the Purchase Price.  In
lieu of the issuance of Common Shares upon exercise of Rights, the Board of
Trustees may under certain circumstances, and if there is an insufficient number
of Common Shares authorized but unissued to permit the exercise in full of the
Rights, the Board is required to, take such action as may be necessary to cause
the Company to issue or pay upon the exercise of Rights, cash (including by way
of a reduction of the Purchase Price), property, other securities or any
combination of the foregoing having an aggregate value equal to that of the
Common Shares which otherwise would have been issuable upon exercise of the
Rights.  The Company may permit the Rights to be exercised for 50% of the Common
Shares (or cash, property or other securities that may be substituted for Common
Shares) that would otherwise be purchasable upon exercise thereof in
consideration of the surrender of the Rights so exercised and without other
payment of the Purchase Price.

                                      -2-
<PAGE>
 
     In the event that, after any person or group becomes an Acquiring Person,
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, proper
provision will be made so that each holder of a Right will thereafter have the
right to receive, upon the exercise thereof at the then current Purchase Price,
a number of shares of common stock of the acquiring company having a market
value (determined in accordance with the Rights Agreement) equal to two times
the Purchase Price.

     At any time after any person or group becomes an Acquiring Person and prior
to the acquisition by that person or group of 50% or more of the outstanding
Common Shares, the Board of Trustees may exchange the Rights (other than Rights
owned by that person or group which will have become void), in whole or in part,
at an exchange ratio of one Common Share (or one one-hundredth of a
Participating Preferred Share) per Right (subject to adjustment).

     As soon as practicable after the Distribution Date, the Company is
obligated to use its best efforts to file a registration statement under the
Securities Act of 1933, as amended, relating to the securities issuable upon
exercise of Rights and to cause such registration statement to become effective
as soon as practicable.

     At any time prior to the end of the tenth business day (or such specified
or unspecified later date as may be determined by the Board of Trustees prior to
such tenth day) following the first date of public announcement by the Company
that a person has become an Acquiring Person (the "Shares Acquisition Date"),
the Board of Trustees may redeem the Rights, in whole but not in part, at a
redemption price of $0.01 per Right (the "Redemption Price"), payable in cash,
Common Shares or any other form of consideration deemed appropriate by the Board
of Trustees. The redemption of the Rights may be made effective at such time, on
such basis and with such conditions as the Board of Trustees in its sole
discretion may establish. Immediately upon the effectiveness of 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.

     The terms of the Rights may be amended by the Board of Trustees without the
consent of the holders of the Rights, provided, however, that no supplement or
amendment shall be made which changes the Redemption Price, the Final Expiration
Date, the Purchase Price or the number of Participating Preferred Shares for
which a Right is exercisable, except that until a person or group of persons
becomes an Acquiring Person, the Board may amend the Rights Agreement to
increase the Purchase Price or extend the Final Expiration Date.

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

     The Rights have certain anti-takeover effects.  The Rights will cause
substantial dilution to a person or group that attempts to acquire the Company
on terms not approved by the Board of Trustees.  The Rights should not interfere
with any merger or other business combination approved by the Board of Trustees
since the Rights may be redeemed by the Company at the Redemption Price prior to
and, under certain circumstances, after the time that a person or group has
acquired beneficial ownership of 15% or more of the Common Shares.

                                      -3-
<PAGE>
 
     The Rights Agreement, which specifies the terms of the Rights and the
Participating Preferred Shares, as amended and restated, has been filed as an
exhibit to this report and is incorporated herein by reference.  The foregoing
description of the Rights does not purport to be complete and is subject to, and
is qualified in its entirety by reference to, the Rights Agreement, including
the definitions therein of certain terms.

     On September 10, 1998, the Board of Trustees also made certain
modifications to the By-Laws of Cabot Industrial Trust.  The Amended and
Restated By-Laws are filed as an exhibit to this report and are incorporated
herein by reference.

ITEM 7. FINANCIAL STATEMENTS AND EXHIBITS

     (c) Exhibits

<TABLE>
<CAPTION> 
         Exhibit No.                            Exhibit
         -----------    --------------------------------------------------------
<C>                     <S>
            1           Rights Agreement, dated as of June 11, 1998, and amended
                        and restated as of September 10, 1998, between Cabot
                        Industrial Trust and BankBoston, N.A., as Rights Agent,
                        including Exhibit A thereto (Form of Articles
                        Supplementary relating to the Series A Junior
                        Participating Preferred Shares) and Exhibit B thereto
                        (Form of Right Certificate)

            2           Amended and Restated By-Laws of Cabot Industrial Trust
                        as of September 10, 1998

</TABLE>

                                      -4-
<PAGE>
 
                                   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.


                                    CABOT INDUSTRIAL TRUST



Date: September 14, 1998            By:    /s/ Neil E. Waisnor
                                          ---------------------------------
                                    Name:  Neil E. Waisnor
                                    Title: Senior Vice President - Finance,
                                           Treasurer and Secretary

                                      -5-
<PAGE>
 
                                 EXHIBIT INDEX
                                 -------------


<TABLE>
<CAPTION>
         Exhibit No.                            Exhibit                                Page
         -----------    --------------------------------------------------------       ----
<C>                     <S>                                                            <C>
            1           Rights Agreement, dated as of June 11, 1998, and amended and
                        restated as of September 10, 1998, between Cabot Industrial 
                        Trust and BankBoston, N.A., as Rights Agent, including  
                        Exhibit A thereto (Form of Articles Supplementary relating 
                        to the Series A Junior Participating Preferred Shares) and 
                        Exhibit B thereto (Form of Right Certificate)

            2           Amended and Restated By-Laws of Cabot Industrial Trust as of
                        September 10, 1998

</TABLE>