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May 29, 1998

Mr. Jim Messemer
1030 Bear Gulch Road
Woodside, CA 94062

Dear Jim:

This  letter  is to  confirm  the  agreement  between  you and  Conceptus,  Inc.
("Company") regarding your separation from employment with the Company.

1.   Your  employment  with the Company will terminate on May 31,1998.  Although
     you are not  otherwise  entitled to receive any further  payments  from the
     Company,  after you sign this letter the  Company  will pay you in eighteen
     equal  installments  over a nine month period,  one hundred twelve thousand
     five hundred dollars ($112,500), less all applicable withholdings, which is
     equal to nine (9) months of your current base salary.  The Company will pay
     directly to Guardian your monthly medical  insurance  premiums for a period
     of nine months after May 31, 1998, for the level of your medical  insurance
     coverage in effect on May 29, 1998.

2.   You have been paid  thirteen  thousand  seven hundred forty six dollars and
     sixty four cents  ($13,746.64)  which  represents  all of your  accrued but
     unused  vacation time. You agree that prior to the execution of this letter
     you were not  entitled to receive any further  monetary  payments  from the
     Company,  and that the only  payments and benefits that you are entitled to
     receive from the Company in the future are those  specified in this letter,
     including those referenced in Paragraph "9" of this letter.

3.   You will  also  receive  out  placement  assistance  in the  amount  of two
     thousand five hundred dollars ($2,500).

4.   In consideration for receiving the severance  payments described above, you
     waive and  release  and  promise  never to assert  any  claims or causes of
     action,  whether or not now  known,  against  Company or its  predecessors,
     successors,   subsidiaries,  officers,  directors,  agents,  employees  and
     assign,  with respect to any matter  arising out of or connected  with your
     employment  with  the  Company  or  the  termination  of  that  employment,
     including  without  limitation,  claims of  wrongful  discharge,  emotional
     distress,  defamation,  breach of contract,  breach of the covenant of good
     faith and fair  dealing,  any claims of  discrimination  based on sex, age,
     race,  national origin, or on any other basis, under Title VII of the Civil
     Rights Act of 1964, as amended,  the California Fair Employment and Housing
     Act, the Age  Discrimination  in Employment Act of 1967, and all other laws
     and regulations  relating to employment.  The sole exception to this global
     release  is of any  claims  you  may  have  arising  out  of the  agreement
     referenced in Paragraph "9" of this letter.


1021 Howard Avenue, San Carlos, CA 94070  Phone: 415/802-7240  Fax: 415/508-7600
<PAGE>

James Messemer Separation Agreement
May 29, 1998
Page Two

5.   You  expressly  waive and  release  any and all rights and  benefits  under
     Section 1542 of the Civil Code of the State of California (or any analogous
     law of any other state),  which reads as follows:  "A general  release does
     not extend to claims which the  creditor  does not know or suspect to exist
     in his favor at the time of executing the release,  which, if known by him,
     must have materially affected his settlement with the debtor."

6.   At all times in the future,  you will remain bound by  Confidentiality  and
     Nondisclosure  Agreement  signed by you on January 7, 1993, a copy of which
     is attached.

7.   Your  stock  options  dated  6/7/94  and  7/11/95  will be fully  vested on
     5/31/98,  after which you have sixty days to exercise  your options for the
     vested but unexercised shares.

8.   You agree  that you will not  disclose  to others the fact or terms of this
     letter,  except that you may disclose such  information to your attorney or
     accountant in order for such individuals to render services to you.

9.   You agree that except as  expressly  provided in this letter and the letter
     from William  Anderson to Gale Borden dated April 7, 1998,  the contents of
     which letter are deemed to be a part of this letter agreement,  this letter
     renders  null and void any and all  prior  agreements  between  you and the
     Company.

Please indicate your agreement with the above terms by signing below.

Sincerely,

/s/  Kathryn Tunstall

Kathryn Tunstall
President and CEO

My  agreement  with  the  above  terms  is  signified  by  my  signature  below.
Furthermore,  I acknowledge that I have read and understand the foregoing letter
and that I sign this release of claims voluntarily,  with full appreciation that
I am forever foreclosed from pursuing any of the rights I have waived.

Signed: /s/ James Messmer                                   Dated: 5/29/98
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