United States

                      SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                     Form 15

CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF
  THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS
     UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934.
                        Commission File Number 0-19392

                              DIANON Systems, Inc.
_____________________________________________________________________________
               (Exact name of registrant as specified in its charter)

      200 Watson Boulevard, Stratford, Connecticut 06615   (203) 381-4000
_____________________________________________________________________________
(Address, including zip code, and telephone number, including area code, of
                  registrant's principal executive offices)

                   Common Stock, par value $0.01 per share
_____________________________________________________________________________
          (Title of each class of securities covered by this Form)

                                     None
_____________________________________________________________________________
(Titles of all other classes of securities for which a duty to file reports
                      under section 13(a) or 15(d) remains)


Please place an X in the box(es) to designate the appropriate rule
provisions(s) relied upon to terminate or suspend the duty to file reports:

Rule 12g-4(a)(1)(i)   [X]                   Rule 12h-3(b)(1)(i)   [X]
Rule 12g-4(a)(1)(ii)  [_]                   Rule 12h-3(b)(1)(ii)  [_]
Rule 12g-4(a)(2)(i)   [_]                   Rule 12h-3(b)(2)(i)   [_]
Rule 12g-4(a)(2)(ii)  [_]                   Rule 12h-3(b)(2)(ii)  [_]
                                                 Rule 15d-6 ----  [_]

Approximate number of holders of record as of the certification or notice
date: 0

Pursuant to the requirements of the Securities Exchange Act of 1934, DIANON
Systems, Inc. has caused this certification/notice to be signed on its behalf
by the undersigned duly authorized person.


Date:  January 17, 2003                   By:  /s/ Bradford T. Smith
                                               -----------------------------
                                               Bradford T. Smith
                                               Secretary

Instruction: This form is required by Rules 12g-4, 12h-3 and 15d-6 of the
General Rules and Regulations under the Securities Exchange Act of 1934. The
registrant shall file with the Commission three copies of Form 15, one
of which shall be manually signed. It may be signed by an officer of the
registrant, by counsel or by any other duly authorized person. The name and
title of the person signing the form shall be typed or printed under the
signature.