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                                                               EXHIBIT 10.17


                                January 13, 1999


PERSONAL AND CONFIDENTIAL
-------------------------

Teresa Pippin
101 Fountain Hills Road
Garland, Texas  75044


Dear Teresa:

                  On behalf of Tekelec, I am pleased to offer you employment as
Vice President, Human Resources of Tekelec, on the terms and conditions set
forth in this letter. As Vice President, Human Resources, you will report
directly to Tekelec's Chief Executive Officer, will be principally responsible
for Tekelec's human resources matters and will have such other duties and
responsibilities as may be delegated to you from time to time by the Chief
Executive Officer or the Board of Directors. You may select your start date so
long as it is on or before February 15, 1999.

                  Your compensation and benefits will be as follows:

                  1.  Your starting annual base salary will be $200,000 (i.e.,
$7,692.31 per bi-weekly period).

                  2.  You will be eligible to participate in Tekelec's 1999
Officer Bonus Plan, with your participation to be calculated as if you were a
full time employee as of January 1, 1999 and determined in accordance with a
percentage of your 1999 base salary. Under the terms of the 1999 Officer Bonus
Plan, you will be eligible to receive up to 50% of your annual base salary as a
cash bonus if Tekelec achieves certain financial milestones in 1999. For 1999,
you will be guaranteed a minimum bonus of $50,000 which will be paid during the
first quarter of 2000.

                  3.  You will be entitled to take four weeks personal time
annually.

                  4.  You will receive applicable benefits, including health,
dental, vision, long-term disability and life insurance, as are generally
provided to Tekelec's executive officers.

                  5.  You will be offered the opportunity to participate in
Tekelec's Employee Stock Purchase Plan and 401(k) Plan upon your satisfaction of
the eligibility requirements for such plans.


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Teresa Pippin
January 13, 1999
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                  6.  You will be covered by Tekelec's Officer Severance Plan (a
copy of which has been previously provided to you).

                  7.  The Compensation Committee of Tekelec will grant to you
stock options (incentive stock options to the maximum extent permitted under
law, with the balance being nonstatutory stock options) under Tekelec's 1994
Stock Option Plan (the "Plan") to purchase 180,000 shares of Tekelec Common
Stock ("Options"), effective as of the later of your start date or the date of
the Compensation Committee's action granting such options (the "grant date").
The exercise price of your Options will be equal to the closing price of
Tekelec's Common Stock on the grant date (as reported in The Wall Street Journal
on the first business day following the grant date). Your Options will vest to
the extent of 36,000 shares on the one-year anniversary of your start date. The
remaining 144,000 shares will vest and become exercisable cumulatively in 16
equal quarterly installments of 9,000 shares each, with the first installment
vesting on June 30, 2000 and one additional installment vesting on the last day
of each calendar quarter thereafter as long as you remain an employee of
Tekelec. Your Options will expire, to the extent previously unexercised, upon
the earlier of ten years from the date of grant or a date not less than three
months after you cease to be a Tekelec employee as determined in accordance with
the terms of the Plan. The Options will in all respects be subject to the terms
and provisions of the Plan and the stock option agreement evidencing the grant
of the Options. In addition to the foregoing grant, it is anticipated that the
Compensation Committee will periodically, typically annually, consider whether
additional options should be granted to you while you remain an officer of the
Company.

                  8.  Although your position will be based in Dallas, Texas, 
your duties will require you to travel as needed to Tekelec offices worldwide.

                  You are aware that Tekelec prohibits employees from unlawfully
using confidential or proprietary information belonging to any other person or
entity. By signing the enclosed copy of this letter, you agree not to disclose
or use or induce Tekelec or any of its employees to use any trade secrets or
confidential or proprietary information belonging to any of your former
employers.

                  As a condition of commencing your employment with Tekelec, you
will be required to sign Tekelec's standard "Confidentiality and Non-Disclosure
Agreement and Assignment of Rights" (a copy of which will be provided to you
under separate cover). As with every Tekelec employee, you reserve the right to
terminate your employment at any time, and we reserve the right to terminate
your employment at will. We hope and expect, however, that this will be a long
and mutually beneficial relationship.


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Teresa Pippin
January 13, 1999
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                  This letter agreement contains our entire understanding with
respect to your employment with Tekelec. The provisions of this letter may be
amended only by a writing signed by you and Tekelec. If you have any questions
about the meaning of any of the terms or provisions included herein, please let
me know at your earliest convenience. This letter agreement shall be construed
under the laws of California.

                  Teresa, we believe that Tekelec can provide you with
opportunities for professional growth and financial return. We look forward to
working with you and to a mutually fulfilling and rewarding relationship.

                  If this letter agreement is acceptable to you, then please
acknowledge your acceptance by signing and dating the enclosed copy of this
letter agreement where indicated below and then faxing (fax number:
818.880.0176) and returning such signed copy to me for receipt no later than
January 21, 1999.

                                           Sincerely,


                                           /s/ Michael L. Margolis
  
                                           Michael L. Margolis
                                           Chief Executive Officer and President



Acknowledged and Accepted:

     /s/ Teresa Pippin
----------------------------------         Date:  January 21, 1999
         Teresa Pippin