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                                                                   Exhibit 10.12

                               CYTYC CORPORATION
 
                      DIRECTOR DEFERRED COMPENSATION PLAN
 
  1. Purpose. Cytyc Corporation, a Delaware corporation (the "Company"),
hereby adopts this Director Deferred Compensation Plan (the "DDC Plan") to
promote the long-term growth and financial success of the Company by
attracting and retaining non-employee directors of outstanding ability and
promoting a greater identity of interest between the Company's non-employee
directors and its stockholders.
 
  The DDC Plan is intended to allow participating non-employee directors to
meet the requirements of, and be treated as "disinterested persons" with
respect to, other stock plans of the Company, as defined in Rule 16b-3 ("Rule
16b-3") of the Securities Exchange Act of 1934, as amended.
 
  2. Administration.
 
    (a) The DDC Plan shall be administered by a committee (the "DDC
  Committee") appointed by the Board of Directors of the Company (the
  "Board") consisting of one employee director and the secretary of the
  Company. The DDC Committee may be changed at any time in the discretion of
  the Board.
 
    (b) The DDC Committee shall have the authority (i) to exercise all of the
  powers granted to it under the DDC Plan, (ii) to construe, interpret and
  implement the DDC Plan and all relevant documents, (iii) to prescribe,
  amend and rescind rules relating to the DDC Plan, and (iv) to make any
  determination necessary or advisable in administering the DDC Plan.
 
    (c) The determination of the DDC Committee on all matters relating to the
  DDC Plan, or any document executed pursuant to the DDC Plan, shall be
  conclusive.
 
    (d) No member of the DDC Committee shall be liable for any action or
  determination made in good faith with respect to the DDC Plan.
 
  3. Eligibility. Only directors of the Company who are not employees of the
Company or any affiliate of the Company ("Eligible Directors") shall
participate in the DDC Plan.
 
  4. Common Shares Subject to the DDC Plan.
 
    4.1 Shares. For purposes of the DDC Plan, "Shares" shall mean shares of
  common stock, par value $.01 per share, of the Company and any other stock
  into which such common stock shall thereafter be changed by reason of any
  merger, reorganization, recapitalization, consolidation, split-up,
  combination of shares or similar event as set forth in and in accordance
  with this Section 4.
 
    4.2 Shares Available for Awards. Subject to Section 4.3 (relating to
  adjustments upon changes in capitalization), as of any date, the total
  number of Shares issuable under the DDC Plan shall be issued from the
  shares authorized for issuance pursuant to the Company's 1995 Stock Plan,
  including any successor plan, and/or any shares repurchased by the Company
  on the open market.
 
    4.3 Adjustments. In the event of any merger, reorganization,
  recapitalization, consolidation, sale or other distribution of all or
  substantially all of the assets of the Company, any stock dividend, split,
  spin-off, split-up, split-off, distribution of securities or other property
  by the Company, or other change in the Company's corporate structure
  affecting the Shares, the number of Shares issuable under the DDC Plan and
  the Share Units (as defined in Section 5.3(b)), then credited pursuant to
  Section 5.3 shall be appropriately adjusted as determined by the DDC
  Committee in its sole discretion.
 
  5. Payment of Retainer, Meeting and/or Committee Fees.
 
    5.1 In General. Subject to Sections 5.2 through 5.6 below, commencing on
  the DDC Plan Effective Date (as herein defined), each Eligible Director may
  elect to receive payment of (a) the annual retainer payable to such
  Director for services as a member of the Board and its committees (the
  "Retainer") and/or
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  (b) fees payable to such Director for meetings of the Board or committees
  of the Board ("Meeting Fees" and "Committee Fees" together with the
  "Retainer" collectively, "Fees"), (i) in cash; or (ii) in Shares (the
  "Current Payment Election"), in accordance with Section 5.2. Alternatively,
  each Eligible Director may elect to defer such payments, payable in cash or
  in Shares (the "Deferred Payment Election"), in accordance with the
  provisions of Section 5.3. In the absence of any Current Payment Election
  or Deferred Payment Election, all payments of Fees shall be paid to the
  Eligible Directors in cash.
 
    5.2 Election to Receive Shares Without Deferral. An Eligible Director may
  elect, with respect to any calendar year, to receive payment of each type
  of Fees due for such calendar year in Shares (the "Current Payment
  Election"), valued at their Fair Market Value on the date on which such
  amounts become payable, by submitting an election form ("Current Payment
  Election Form") to the Company within 30 days after the DDC Plan Effective
  Date, or for subsequent calendar years, at least 30 days prior to the
  beginning of any calendar year. Except as provided herein, the beginning of
  such calendar year shall be the effective date of such election for payment
  of such Fees. A Current Payment Election shall be effective only with
  respect to Fees that become payable after the effective date. Any election
  made under this Section 5.2 shall continue in full force and effect,
  including for subsequent calendar years, until revoked by written notice to
  the Company, until superseded by a new Current Payment Election Form, or
  unless no longer permitted by law or regulations (including Rule 16b-3).
 
    5.3 Elective Deferrals. An Eligible Director may elect to defer the
  payment of Fees by electing to have the Fees paid in cash or credited to an
  account as Shares ("Deferred Amount"), by submitting an election form (a
  "Deferred Payment Election Form") to the Company within 30 days after the
  DDC Plan Effective Date with respect to amounts payable in 1998, or, for
  subsequent calendar years, at least 30 days prior to any calendar year in
  which such Fees would otherwise be paid to the Eligible Director. Except as
  provided herein, any such election shall become effective for the calendar
  year following the calendar year in which such Deferred Payment Election
  Form is submitted to the Company. An election under this Section 5.3 shall
  continue in effect, until the end of the calendar year in which it is
  revoked by written notice to the Company, until it is superseded by a new
  Deferred Payment Election Form, or immediately, if no longer permitted by
  law or regulation (including under Rule 16b-3). An Eligible Director may
  designate, in a Deferred Payment Election Form, one or more beneficiaries
  to receive any distributions under the DDC Plan upon the death of the
  Eligible Director, and such designation may be changed at any time by
  submitting a new designation in writing to the Company, which shall become
  effective immediately upon receipt by the Company. If no beneficiary is
  designated by an Eligible Director, distributions under the DDC Plan shall
  be made to the Eligible Director's estate.
 
      (a) Cash Account: The Deferred Payment Election Form shall indicate:
    (i) any Fees to be allocated to the "Cash Account" (the "Deferred
    Amount"); and (ii) the date on which the commencement of payments of
    Deferred Amounts (the "Distribution Date") should begin, as
    contemplated by Section 5.4(a).
 
      (b) Share Account: The Deferred Payment Election Form shall indicate:
    (i) any Fees to be credited to an account (a "Share Account") in units
    which are equivalent in value to Shares ("Share Units") which shall
    comprise the "Deferred Amount". The Deferred Amount allocated to the
    Share Account shall be credited to the Share Account no later than the
    end of the month during which the Eligible Director becomes entitled to
    payment of the Retainer, Meeting and/or Committee Fees. The number of
    Share Units credited to such Share Account shall be an amount equal to
    the result obtained by dividing (i) the Deferred Amount allocated to
    the Share Account by (ii) the Fair Market Value of a Share on the
    business day on which the Eligible Director becomes entitled to payment
    of the Fees. If Share Units exist in an Eligible Director's Share
    Account on a dividend record date for the Company's Shares, the Share
    Account shall be credited, on the dividend payment date, with an
    additional number of Share Units equal to (i) the cash dividend paid on
    one Share, times (ii) the number of Share Units in the Share Account on
    the dividend record date, divided by (iii) the Fair Market Value of a
    Share on the dividend payment date.
 
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    5.4 Distributions.
 
      (a) Distribution Date. Each Eligible Director shall designate, on a
    Deferred Payment Election Form, one of the following dates as a
    Distribution Date with respect to the Deferred Amount credited to the
    Eligible Director's Account thereafter: (i) the first day of a month
    following the termination of service or retirement of the Eligible
    Director as a member of the Board, (ii) a fixed date in the future at
    least one year after the date of such deferral as specified on a
    Deferred Payment Election Form, but no later than December 12, 2005; or
    (iii) the earlier to occur of (i) or (ii). In the event of an Eligible
    Director's death, all Deferred Amounts shall be paid no later than the
    end of the month following the occurrence of such event.
 
      (b) Share Account Distribution Method. Distributions shall be made
    from the Eligible Director's Share Account in a single payment in the
    form of whole Shares, and cash representing any fractional interest in
    a Share.
 
      (c) Emergency Distribution. In the event that an Eligible Director
    encounters an unanticipated emergency that is caused by an event beyond
    the control of such Eligible Director and/or his/her beneficiary (if
    any) which would result in severe financial hardship if early
    withdrawal were not permitted, the Eligible Director may submit a
    written request to the DDC Committee outlining the nature of such
    emergency and the portion of any Deferred Amount (the "Early
    Distribution") necessary to meet such emergency. The DDC Committee, in
    its sole discretion, shall determine the amount of any such Early
    Distribution to be paid in accordance with the terms of this Section
    5.4.
 
    5.5 Interest on Cash Deferrals. Any payments due an Eligible Director and
  deferred into the Cash Account shall be credited as of January 1, April 1,
  July 1 and October 1 of each year, with an amount equal to the balance in
  said account at the end of the preceding quarter, multiplied by the
  percentage that represents 25% of the prime rate of interest as reflected
  in the Wall Street Journal on the last business day of the preceding
  quarter.
 
  6. Definition of Fair Market Value. For purposes of this DDC Plan, in
respect to the valuation of Shares, if the Company's Common Stock is publicly
traded, "fair market value" shall be determined as of the last business day
for which prices or quotes are available and shall mean (a) the average (on
that date) of the high and low prices of the Common Stock on the principal
national securities exchange on which the Common Stock is traded, if the
Common Stock is then traded on a national securities exchange; or (b) the last
reported sale price (on that date) of the Common Stock on the Nasdaq Stock
Market, if the Common Stock is not then traded on a national securities
exchange; or (c) the closing bid price (or average of bid prices) last quoted
(on that date) by an established quotation service for over-the-counter
securities, if the Common Stock is not reported on the Nasdaq Stock market.
However, if the Common Stock is not publicly traded at the time a Share is to
be credited to a Share Account under the DDC Plan, "fair market value" shall
be deemed to be the fair value of the Common Stock as determined by the DDC
Committee after taking into consideration all factors which it deems
appropriate, including, without limitation, recent sale and offer prices of
the Common Stock in private transactions negotiated at arm's length; provided,
however, that the "fair market value" of the stock issuable upon a
Distribution Date pursuant to the DDC Plan within 120 days prior to the time
the Company's Common Stock is publicly traded shall be deemed to be equal to
the initial per share purchase price at which the Company's Common Stock is
offered to the public.
 
  7. Definition of Disability. "Disability" shall mean any condition which
causes an Eligible Director to be unable to substantially perform services as
a member of the Board for a period of at least three consecutive months, or
for an aggregate of at least five months within any 12-month period.
 
  8. Issuance of Certificates and Legal Compliance.
 
    8.1 Restrictions on Transferability. All Shares delivered under the DDC
  Plan shall contain such restrictive legends and be subject to such stop-
  transfer orders and other restrictions as the Company may deem advisable or
  legally necessary under any laws, rules, regulations and other legal
  requirements
 
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  including, without limitation, those of any stock exchange upon which the
  Shares are then listed and any applicable federal, state or foreign
  securities law.
 
    8.2 Compliance with Laws. Anything to the contrary herein
  notwithstanding, the Company shall not be required to issue any Shares
  under the DDC Plan if, in the opinion of the Company's General Counsel, the
  issuance and delivery of such Shares would constitute a violation by the
  Eligible Director or the Company of any applicable law or regulation of any
  governmental authority, including, without limitation, federal and state
  securities laws and the rules of any stock exchange on which the Company's
  securities may then be listed. If and to the extent that the DDC Committee
  determines that it would be illegal, impractical or inadvisable to issue
  Shares under the DDC Plan, or to the extent Shares are unavailable, the DDC
  Committee shall make any distribution of Shares otherwise required under
  the DDC Plan in cash.
 
    8.3 Listing, Registration and Legal Compliance. If the DDC Committee
  shall at any time determine that any Consent (as hereinafter defined) is
  necessary or desirable as a condition of, or in connection with, the
  granting of any award under the DDC Plan, the issuance of Shares or other
  rights hereunder or the taking of any other action hereunder (each such
  action being hereinafter referred to as a "Plan Action"), then such Plan
  Action shall not be taken, in whole or in part, unless and until such
  Consent shall have been effected or obtained. The term "Consent" as used
  herein with respect to any Plan Action means (a) the listing, registration
  or qualification of any Shares issued under the DDC Plan on any securities
  exchange or under any foreign, federal, state or local law, rule or
  regulation, (b) any and all consents, clearances and approvals in respect
  of a Plan Action by any governmental or other regulatory bodies, or (c) any
  and all written agreements and representations by an Eligible Director with
  respect to the disposition of Shares or with respect to any other matter
  which the DDC Committee shall deem necessary or desirable in order to
  comply with the terms of any such listing, registration or qualification or
  to obtain an exemption from the requirement that any such listing,
  qualification or registration be made.
 
    8.4 Governing Law. The DDC Plan shall be governed by, and construed in
  accordance with, the laws of the Commonwealth of Massachusetts.
 
    8.5 Rights as a Shareholder. An Eligible Director shall have no rights as
  a shareholder of the Company with respect to any Shares issuable under the
  DDC Plan until such Shares have been delivered to the Eligible Director.
 
  9. Tax Related Issues.
 
    9.1 Withholding and Other Obligations. The Company shall require as a
  condition of delivery of any Shares or payment of any Deferred Amount to an
  Eligible Director that, if applicable, such Director remit an amount
  sufficient to satisfy any foreign, federal, state, local and other
  governmental withholding tax requirements relating thereto and any
  indebtedness or other obligation of the Eligible Director to the Company.
 
    9.2 Unfunded DDC Plan. The DDC Plan shall be unfunded and shall not
  create (or be construed to create) a trust or separate fund. The DDC Plan
  shall not establish any fiduciary relationship between the Company and any
  Eligible Director or other person and shall constitute a mere promise by
  the Company to make payments in the future. To the extent any person holds
  any rights by virtue of a pending deferral under the DDC Plan, such rights
  shall be no greater than the rights of an unsecured general creditor of the
  Company.
 
    9.3 Rights Not Transferable or Subject to Alienation. No rights granted
  to an Eligible Director under this DDC Plan may be sold, assigned or
  otherwise transferred by the Eligible Director other than by will or the
  laws of descent or distribution; all rights granted to an Eligible Director
  under this DDC Plan may be exercised during the Eligible Director's
  lifetime only by such Eligible Director. An Eligible Director's rights to
  payments under the DDC Plan are not subject in any manner to anticipation,
  alienation, sale, transfer, assignment, pledge, encumbrance, attachment or
  garnishment by his creditors or his beneficiaries.
 
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  10. DDC Plan Amendments and Termination. The Board may suspend or terminate
the DDC Plan at any time and may amend it at any time, in whole or in part,
provided that no amendment or termination may adversely affect any rights of
any Eligible Director that have accrued prior to the date of such amendment or
termination, and provided, further, that any amendment for which shareholder
approval is required by law or in order to maintain continued qualification of
the DDC Plan under Rule 16b-3, shall not be effective until such approval has
been obtained.
 
  11. Right of Discharge Reserved. Nothing in the DDC Plan shall confer upon
any Eligible Director the right to continue in the service of the Company or
affect any right that the Company may have to terminate the service of such
Eligible Director.
 
  12. Other Payments or Awards. Nothing contained in the DDC Plan shall be
deemed in any way to limit or restrict the Company, any affiliate, or the
Board from making any award or payment to any person under any other plan,
arrangement or understanding, whether now existing or hereafter in effect,
other than by use of the shares authorized under the Company's 1995 Stock
Plan.
 
  13. Severability. If any portion of the DDC Plan is declared by any court or
governmental authority to be invalid, such invalidity shall not affect any
portion not declared to be invalid. Any portion so declared to be invalid
shall, if possible, be construed in a manner which will give effect to the
terms of such portion to the fullest extent possible while remaining valid.
 
  14. Notices. All notices and other communications hereunder shall be given
in writing and shall be personally delivered or sent by registered or
certified mail, return receipt requested, or by reputable overnight delivery
service. Any notice shall be deemed given on the date of delivery or mailing,
and if mailed, shall be addressed (a) to the Company, at 85 Swanson Road,
Boxborough, MA 01719, Attention: DDC Committee (c/o President), and (b) to an
Eligible Director, at the Eligible Director's principal residential address
last furnished to the Company. Either party may, by notice, change the address
to which notice to such party is to be given.
 
  15. Section Headings. The Section headings contained herein are for
convenience only and are not intended to define or limit the contents of said
Sections.
 
  16. Effective Date. This DDC Plan shall become effective immediately upon
the approval of the DDC Plan by the Board, as reflected in a Board Resolution
(the "DDC Plan Effective Date").
 
  17. Exculpation. It is understood that the obligations incurred by the
Company with respect to this DDC Plan do not constitute personal obligations
of the Directors, officers, employees or shareholders and shall not create or
involve any claim against, or personal liability on the part of, them or any
of them. The Eligible Directors agree not to seek recourse against any such
Directors, officers, employees or shareholders, or any of them or any of their
personal assets for satisfaction of any liability under or with respect to the
DDC Plan.
 
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