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EXHIBIT 31.1

Certificate of Chief Executive Officer of
Tekelec pursuant to

Rule 13a-14(a) under the Exchange
Act,


as adopted pursuant to Section 302 of the
Sarbanes-Oxley Act of 2002


I, Frederick M. Lax, certify that:

1. I have reviewed this annual report on
Form 10-K of Tekelec;

2. Based on my knowledge, this annual report
does not contain any untrue statement of a material fact or omit
to state a material fact necessary to make the statements made,
in light of the circumstances under which such statements were
made, not misleading with respect to the period covered by this
annual report;

3. Based on my knowledge, the financial
statements, and other financial information included in this
annual report, fairly present in all material respects the
financial condition, results of operations and cash flows of the
registrant as of, and for, the periods presented in this annual
report;

4. The registrants other certifying
officer(s) and I are responsible for establishing and
maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
registrant and have:



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| | a) Designed such disclosure controls and
    procedures, or caused such disclosure controls and procedures to
    be designated under our supervision, to ensure that material
    information relating to the registrant, including its
    consolidated subsidiaries, is made known to us by others within
    those entities, particularly during the period in which this
    annual report is being prepared;      
|
| | b) Evaluated the effectiveness of the
    registrants disclosure controls and procedures and
    presented in this annual report our conclusions about the
    effectiveness of the disclosure controls and procedures, as of
    the end of the period covered by this annual report based on
    such evaluation; and                                                                                                
|
| | c) Disclosed in the annual report any change
    in the registrants internal control over financial
    reporting that occurred during the registrants most recent
    fiscal quarter (the registrants fourth fiscal quarter in
    the case of an annual report) that has materially affected, or
    is reasonably likely to materially affect, the registrants
    internal control over financial reporting; and

5. The registrants other certifying
officer(s) and I have disclosed, based on our most recent
evaluation of internal control over financial reporting, to the
registrants auditors and the audit committee of
registrants board of directors (or persons performing the
equivalent functions):



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| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | a) All significant deficiencies and material
    weaknesses in the design or operation of internal control over
    financial reporting which are reasonably likely to adversely
    affect the registrants ability to record, process,
    summarize and report financial information; and
|
| | b) Any fraud, whether or not material, that
    involves management or other employees who have a significant
    role in the registrants internal control over financial
    reporting.                                                                                                   

Date: March 15, 2004

| |                                          
| | -----------------------------------------
| | /s/ FREDERICK M. LAX                     
| |                                          
| | Frederick M. Lax                         
| | President and Chief Executive
    Officer