SCHEDULE 14A INFORMATION

                Proxy Statement Pursuant to Section 14(a) of the

                         Securities Exchange Act of 1934


Filed by the Registrant [X]

Filed by a Party other than the Registrant [ ]

Check the appropriate box:

[ ]  Preliminary  Proxy Statement

[ ]  Confidential, for Use of the Commission Only (as permitted by
     Rule 14a-6(e)(2))

[X]  Definitive Proxy Statement

[ ]  Definitive  Additional  Materials

[ ]  Soliciting Material Pursuant to ss. 240.14a-11(c) or ss. 240.14a-12

                              DIANON Systems, Inc.
- --------------------------------------------------------------------------------
                (Name of Registrant as Specified In Its Charter)

                              DIANON Systems, Inc.
- --------------------------------------------------------------------------------
                   (Name of Person(s) Filing Proxy Statement)

Payment of Filing Fee (Check the appropriate box):

[X]  No fee required.

[ ]  $500 per each party to the controversy pursuant to Exchange Act
     Rule 14a-6(i)(3).

[ ]  Fee Computed on table below per Exchange Act Rules 14a-6(i)(4) and 0-11.

     1)   Title of each class of securities to which transaction applies:

     2)   Aggregate number of securities to which transaction applies:

     3)   Per unit  price  or other  underlying  value of  transaction  computed
          pursuant to Exchange Act Rule 0-11:

     4)   Proposed maximum aggregate value of transaction:

     5)   Total fee paid:

[ ]  Fee paid previously with preliminary materials.

[ ]  Check box if any part of the fee is offset as provided by Exchange Act Rule
     0-11 (a)(2) and identify the filing for which the  offsetting  fee was paid
     previously.  Identify the previous filing by registration statement number,
     or the Form or Schedule and the date of its filing.

     1)   Amount Previously Paid:

     2)   Form, Schedule or Registration Statement No.:

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     4)   Date Filed:




                              DIANON SYSTEMS, INC.

                    NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

                                OCTOBER 21, 1999


      The Annual  Meeting  of the  shareholders  of DIANON  Systems,  Inc.  (the
"Company")  will be held at the Company's  corporate  headquarters at 200 Watson
Boulevard, Stratford, Connecticut, on Thursday, October 21, 1999, at 10:00 A.M.,
for the following purposes:

            (1)   To elect directors for the ensuing year;

            (2)   To approve the adoption of the Employee Stock Purchase Plan;

            (3)   To approve the adoption of the 1999 Stock Incentive Plan;

            (4)   To  ratify  the  appointment  of Arthur  Andersen,  LLP as the
                  independent public accountants of the Company for the calendar
                  year ended December 31, 1999; and

            (5)   To transact  such other  business as may properly  come before
                  the meeting or any adjournment or adjournments thereof.

      Only  shareholders of record at the close of business on September 8, 1999
will be entitled to vote at the Annual Meeting. A list of shareholders  eligible
to vote at the Annual  Meeting will be available  for  inspection  at the Annual
Meeting  and during  business  hours from  October  11,  1999 to the date of the
Annual Meeting at the Company's corporate headquarters.

      Whether you expect to attend the Annual Meeting or not, your proxy vote is
important.  To assure your  representation at the meeting,  please sign and date
the enclosed proxy card and return it promptly in the enclosed  envelope,  which
requires no additional postage if mailed in the United States or Canada.

                                           By Order of the Board of Directors


                                               /s/ David R. Schreiber
                                               ----------------------
                                                   David R. Schreiber
                                                   Corporate Secretary


200 Watson Boulevard
Stratford, Connecticut 06615
September 20, 1999

            IT IS IMPORTANT THAT THE ENCLOSED PROXY CARD BE COMPLETED
                              AND RETURNED PROMPTLY





                              DIANON SYSTEMS, INC.
                                 PROXY STATEMENT


September 20, 1999

      This Proxy Statement is furnished in connection  with the  solicitation of
proxies by the Board of  Directors  of DIANON  Systems,  Inc.  ("DIANON"  or the
"Company") for use at the Annual Meeting of its  shareholders  to be held at the
Company's corporate headquarters at 200 Watson Boulevard, Stratford, Connecticut
on Thursday, October 21, 1999, at 10:00 A.M.

      Shares cannot be voted at the Annual  Meeting  unless the owner thereof is
present in person or by proxy.  All properly  executed and unrevoked  proxies in
the  accompanying  form that are received in time for the Annual Meeting will be
voted at the Annual Meeting or any  adjournment  thereof in accordance  with any
specification  thereon,  or if no specification is made, will be voted "FOR" the
election of the named  director  nominees and approval of the other proposal set
forth in the Notice of Annual Meeting of Shareholders of the Company.  The Board
of  Directors  of the  Company  knows of no other  matters  which may be brought
before the Annual Meeting.  However, if any other matters are properly presented
for action,  it is the intention of the named proxies to vote on them  according
to their  best  judgment.  Any  person  giving a proxy may  revoke it by written
notice to the Company at any time prior to exercise of the proxy.  In  addition,
although  mere  attendance  at the Annual  Meeting will not revoke the proxy,  a
person  present at the Annual  Meeting may withdraw his or her proxy and vote in
person. Rights of appraisal or similar rights of dissenters are not available to
shareholders  of the Company  with respect to any matter to be acted upon at the
Annual Meeting.

      The Annual Report on form 10-K of the Company  (which does not form a part
of these proxy solicitation  materials),  as filed with the Securities  Exchange
Commission  and including the financial  statements of the Company,  is enclosed
herewith.

      The mailing  address of the principal  executive  office of the Company is
200 Watson Boulevard, Stratford, Connecticut 06615. This Proxy Statement and the
accompanying  form of proxy are expected to be mailed to the shareholders of the
Company on or about September 20, 1999.



                                VOTING SECURITIES

      The  Company  has only one class of  voting  securities  outstanding,  its
Common Stock,  par value $0.01 per share (the "Common  Stock").  On September 8,
1999, 6,814,967 shares of Common Stock were outstanding.  At the Annual Meeting,
each  shareholder of record at the close of business on September 8, 1999,  will
be entitled to one vote for each share of Common  Stock owned on that date as to
each matter presented at the Annual Meeting.



                              ELECTION OF DIRECTORS

      Unless otherwise  directed,  the persons named in the accompanying form of
proxy  intend to vote at the Annual  Meeting  "FOR" the election of the nominees
named below as directors  of the Company to serve until the next Annual  Meeting
and  until  their  successors  are duly  elected  and  qualified.  THE  BOARD OF
DIRECTORS RECOMMENDS THAT SHAREHOLDERS VOTE "FOR" THE ELECTION OF SUCH NOMINEES.

      If any nominee is unable to stand for  election  when the  election  takes
place,  the shares  represented  by valid  proxies will be voted in favor of the
remaining  nominees and for such person,  if any, as shall be  designated by the
present Board of Directors to replace such nominee.  The Board of Directors does
not presently anticipate that any nominee will be unable to stand for election.

INFORMATION CONCERNING DIRECTORS AND NOMINEES

      The  following  information  with respect to the  principal  occupation or
employment,  other  affiliations and business  experience of each nominee during
the last five years has been furnished to the Company by such nominee. Except as
indicated,  each of the nominees has had the same  principal  occupation for the
last five years.

      Kevin C.  Johnson,  age 44, a Director  since May 1996,  is President  and
Chief Executive  Officer of the Company.  Mr. Johnson joined Dianon as President
in May 1996,  and was appointed to the  additional  position of Chief  Executive
Officer in February  1997.  Formerly,  Mr.  Johnson  was with  Corning  Inc.,  a
manufacturer of specialty materials and a provider of laboratory  services,  for
eighteen  years,  serving most recently as Vice President and General Manager of
Corning Clinical Laboratories' Eastern region in Teterboro, New Jersey.

      John P. Davis,  age 57, a Director  since 1984, has served as a consultant
to the Company since October 1998.  Mr. Davis was President and Chief  Executive
Officer of Infant Advantage,  Inc., a child development  company,  from December
1997  through  June 1998.  From May 1995 through  December  1997,  Mr. Davis was
President and Chief Executive Officer of Calypte  Biomedical Corp., a diagnostic
products  company.  From 1984 to January  1995,  Mr. Davis was an officer of the
Company.  Mr. Davis  joined the Company in January  1984 as President  and Chief
Operating  Officer,  and subsequently  became co-Chief Executive Officer in 1992
and Chief  Executive  Officer in 1994.  In January 1995,  Mr. Davis  resigned as
Chief Executive Officer of the Company and became Vice Chairman of the Board. In
February 1997, Mr. Davis was elected  non-executive  Chairman of the Board.  Mr.
Davis also serves as Chairman of the Board of CytoLogix, Inc.

      Bruce K.  Crowther,  age 47, a Director  since December 1997, is President
and  Chief  Executive  Officer  of  Northwest  Community  Healthcare,  Northwest
Community  Hospital,   in  Arlington  Heights,   Illinois  and  certain  of  its
affiliates.  Mr.  Crowther  is a Fellow of the  American  College of  Healthcare
Executives,  Chairman of the Board of the Illinois  Hospital  and  HealthSystems
Association  and  serves  on the Board of both  Chicago  Hospital  Risk  Pooling
Program  and  Barrington  Bank and  Trust.  Mr.  Crowther  received  an MBA from
Virginia Commonwealth University Medical College in Richmond, VA.

      E. Timothy  Geary,  age 47, a Director since June 1997, had been Chairman,
President  and Chief  Executive  Officer of National  Surgery  Centers,  Inc. of
Chicago,  Illinois,  the leading  independent  owner and operator of  ambulatory
surgery centers in the country, until its acquisition by HealthSouth Corporation
on  July  22,  1998.   Mr.  Geary  is  currently  a  consultant  to  HealthSouth
Corporation.  Prior to founding  National  Surgery  Centers in 1987,  Mr.  Geary
served as a Vice President with Medical Care  International.  Mr. Geary holds an
MBA and AB from the University of Chicago.

      G. S.  Beckwith  Gilbert,  age 57,  a  Director  since  October  1995,  is
President,  Chief  Executive  Officer  and a  Director  of Field  Point  Capital
Management  Company in Greenwich,  Connecticut,  a merchant  banking  firm.  Mr.
Gilbert is also a partner of Wolsey & Co., a merchant banking firm. In addition,
Mr.  Gilbert is  Chairman,  President  and Chief  Executive  Officer of Megadata
Corporation as well as a Director of Davidson Hubeny Brands, Inc. Mr. Gilbert is
a graduate of Princeton University and holds an MBA from New York University. In
February  1997,  the  Board  elected  Mr.  Gilbert  Chairman  of  the  Executive
Committee.

      Jeffrey  L.  Sklar,  age 51,  a  Director  since  1994,  is  Professor  of
Pathology,  Harvard  Medical  School,  and  Director,  Divisions  of  Diagnostic
Molecular Biology and of Molecular  Oncology,  Department of Pathology,  Brigham
and Women's Hospital.  Dr. Sklar has served on numerous editorial boards and has
consulted widely to the biotechnology industry. In addition, Dr. Sklar serves on
the Scientific  Advisory  Committee for Clinical  Science,  The Fred  Hutchinson
Cancer Center,  Seattle,  Washington;  the Scientific  Advisory  Committee,  New
England  Primate  Research  Center,  Harvard  University;  the  External  Review
Committee,  Dana-Farber  Cancer  Institute,  Boston,  and the  Pathology B Study
Section,  National  Institutes of Health. Dr. Sklar also serves as a Director of
Transgenomic,  Inc.  and holds an MD and Ph.D.  from Yale  University  and an MA
(honorary) from Harvard University.

      David R. Schreiber, age 39, has served as Senior Vice President,  Finance,
Chief  Financial  Officer and Corporate  Secretary  since  November 1996 when he
joined  the  Company.   Formerly,   Mr.  Schreiber  was  with  Corning  Clinical
Laboratories,  a provider of  laboratory  services,  for 10 years,  serving most
recently as Vice  President  and  General  Manager of the  laboratory's  Midwest
region. Mr. Schreiber holds an MBA from Northern Illinois University.


COMMITTEES OF THE BOARD

      The  Company's   Board  of  Directors   presently   has  standing   Audit,
Compensation,  and Executive  Committees,  the current  membership and principal
responsibilities  of which are described  below. The Board of Directors does not
have a Nominating Committee.

Audit Committee

      Members:   Mr. Gilbert and Mr. Crowther

      The Audit  Committee's  functions  include  reviewing with the independent
public  accountants the plan for and results of their audit, the adequacy of the
Company's systems of internal  accounting controls and any material breakdown in
such controls. In addition,  the Audit Committee reviews the independence of the
independent  public  accountants  and their fees for  services  rendered  to the
Company.

Compensation Committee

      Members:   Mr. Crowther, Mr. Gilbert and Dr. Sklar

      The Compensation Committee's functions include setting compensation of the
directors and the executive officers.  In addition,  the Compensation  Committee
has the  authority to grant  certain  awards  under the 1991,  1996 and 1999 (if
approved) Stock Incentive Plans.

Executive Committee

      Members:   Mr. Gilbert, Mr. Davis and Mr. Johnson

      The  Executive  Committee's  primary  function is to assist  management in
formulating the Company's long-term strategy.  Mr. Gilbert serves as Chairman of
the Executive Committee.

ATTENDANCE AT BOARD AND COMMITTEE MEETINGS

      During the 1998  fiscal  year the Board of  Directors  held seven  regular
meetings. In addition,  the Audit Committee,  the Compensation Committee and the
Executive  Committee  each met two times.  During such fiscal year each director
attended at least 75% of the aggregate of (i) the regular  meetings of the Board
and (ii) the  meetings  of the  committees  of the Board on which such  director
served.

COMPENSATION OF DIRECTORS

      Directors  who are not  employees  of the Company are paid $1,500 for each
meeting of the Board of  Directors  attended in person and $500 for each meeting
attended by  telephone.  In addition,  committee  members are paid $500 for each
committee  meeting  attended  which  does  not  occur on the same day as a Board
meeting.  Directors are also  reimbursed for expenses to attend  meetings of the
Board and its committees.  In addition, the Company has made payments to Brigham
&  Women's  Hospital,  Inc.,  for  which  Dr.  Sklar is  director,  Division  of
Diagnostic  Molecular  Biology,   Department  of  Pathology.  See  "Compensation
Committee Interlocks and Insider Participation."


      Commencing January 1, 1998, Mr. Davis and Mr. Gilbert,  in connection with
their  capacities  as  non-Executive  Chairman of the Board and  Chairman of the
Executive  Committee,  respectively,  also  receive  $50,000  annually  (payable
monthly at $4,166) and an annual grant of 3,000 stock options,  at a price equal
to the market value on the date of grant,  pursuant to the Company's  1996 Stock
Incentive Plan. They each also received a one-time grant of 13,000 stock options
in December 1997 pursuant to this same plan, in connection  with their  services
in the aforementioned positions during 1997.

      In addition to his aforementioned  duties,  commencing October 1, 1998 Mr.
Davis began serving as a consultant to the Company,  providing approximately two
days per week of consulting  services and  maintaining an office at the Company.
He works closely with the sales and marketing  functions of the Company,  and is
involved in the planning and development of sales training programs, recruiting,
compensation  planning,  market segmentation,  pricing, and national and managed
care marketing programs. As compensation for these services,  Mr. Davis receives
$50,000  annually  (payable  monthly at $4,166),  in  addition  to his  director
compensation  and in addition  to the  $50,000 he  receives  in his  capacity as
non-Executive   Chairman  of  the  Board.  In  connection  with  his  consulting
arrangement,  Mr. Davis was also paid a relocation  reimbursement of $123,667 in
February  1999, and will receive in 2000 a  reimbursement  for the tax effect of
the relocation payment.

      Pursuant to the Company's 1996 Stock Incentive Plan, Directors who are not
employees of the Company receive (i) automatic  initial and quarterly  grants of
stock options with tandem limited stock appreciation rights beginning July 1995,
(ii) automatic quarterly grants of shares of Common Stock beginning January 1997
and (iii)  additional stock options or other awards to the extent granted by the
Board of Directors in its discretion.

      Each initial and  quarterly  stock option which is  automatically  granted
under such plan is  exercisable  for that number of shares  obtained by dividing
$5,000  by the  closing  price of the  Common  Stock on the date of grant and is
exercisable  at that price.  Each such option has a 10-year  term and vests with
respect to 10% of the underlying  shares on the date which is three months after
the date of grant, and an additional 10% at the end of each  three-month  period
thereafter.  Each such  option  can be  exercised  for five  years  following  a
director's  termination  of  service  to the  extent  it  had  vested  prior  to
termination.  Each automatic  quarterly  stock grant is for the number of shares
obtained by dividing $2,000 by the closing price of the Common Stock on the date
of grant, and is fully vested at grant.

      In November 1996, pursuant to authorization by the Board of Directors, the
Company granted to Dr. Sklar an option to purchase 10,000 shares of Common Stock
at an exercise price of $6.375 to compensate him for his services as a Director.
Such option vests 40% on grant, and an additional 20% on each of August 4, 1997,
August 4, 1998 and August 4, 1999.  Such grant is a replacement  of an option to
purchase 10,000 shares of Common Stock  authorized by the Board in 1994, but not
accepted by Dr. Sklar at that time due to the  conditions  of his  employment by
Brigham & Women's Hospital, Inc.

      Mr.  Johnson,  who is an employee of the Company,  receives no  additional
compensation  for his services as Director of the Company.  Mr.  Schreiber  will
receive no additional compensation if elected as Director of the Company.

VOTING FOR DIRECTORS

      Abstentions  are  included  in the  determination  of the  existence  of a
quorum.  Directors are elected by a plurality of the votes of the shares present
in person or  represented  by proxy at the meeting  and  entitled to vote on the
election  of  directors.  An  automated  system  administered  by the  Company's
transfer agent tabulates the votes.  Abstentions are not counted for purposes of
election of directors.




                               EXECUTIVE OFFICERS

      For information with respect to Mr. Johnson,  who is also a Director,  and
Mr.  Schreiber,  who is a nominee for  Director,  see  "Election  of Directors -
Information Concerning Directors and Nominees."

      James B.  Amberson,  age 48, is Senior Vice  President  and Chief  Medical
Officer  of the  Company.  Dr.  Amberson  joined  Dianon  in 1989  as  Director,
Cytometry Business Unit, and has served as Vice President of Pathology Services,
Vice President of Medical  Affairs and Senior Vice President and General Manager
of the Anatomic Pathology Unit before his present position. Prior to joining the
Company,  Dr. Amberson was Assistant Professor of Pathology,  Cornell University
Medical  College  for six years.  Dr.  Amberson  holds an MD from Johns  Hopkins
University and an MBA from Columbia University School of Business.

      Steven T.  Clayton,  age 33,  has  served as Vice  President,  Information
Services  since he joined the  Company in  December  1996.  Prior to joining the
Company,  Mr.  Clayton was with  Corning  Clinical  Laboratories  for nine years
serving most recently as the Midwest Regional  Director of Information  Systems.
Mr. Clayton holds an ASM from Thomas Edison State College.

      Martin  J.  Stefanelli,  age 38,  has  served as  Senior  Vice  President,
Operations  since  October  1998.  He  previously   served  as  Vice  President,
Laboratory  Operations.  Mr.  Stefanelli joined the Company in January 1990 as a
Sales  Representative and subsequently  served as Logistics  Manager,  Marketing
Manager and  Director of  Operations,  Anatomic  Pathology.  Before  joining the
Company,  Mr.  Stefanelli was a captain in the U.S. Army. Mr. Stefanelli holds a
BS from the United States Military Academy.

      Valerie  B.  Palmieri,  age 38,  has  served  as Vice  President,  Service
Operations since November 1998. Ms. Palmieri joined the Company in December 1987
as a Medical  Technologist  and  subsequently  served as Laboratory  Supervisor,
Operations Laboratory Manager,  Director of Operations - Clinical Pathology, and
Director of Service Operations.  Prior to joining the Company,  Ms. Palmieri was
with Park City and Bridgeport Hospital as a Medical  Technologist.  Ms. Palmieri
holds a BS from Western Connecticut State University.


                             EXECUTIVE COMPENSATION

COMPENSATION COMMITTEE REPORT

      The  Compensation  Committee of the Board of Directors of DIANON  Systems,
Inc. (the  "Committee") sets forth its report on executive  compensation  below.
This  Committee  report  documents the  components  of the  Company's  executive
officer compensation programs and describes the basis on which 1998 compensation
determinations were made by the Committee with respect to the executive officers
of  the  Company,  including  the  executive  officers  that  are  named  in the
compensation tables below.

COMPENSATION PROGRAM COMPONENTS

      The Committee is responsible for setting and monitoring the  effectiveness
of the compensation  provided to the Company's Directors and executive officers.
In its  decision-making,  the Committee is guided by a  compensation  philosophy
designed to reward  employees  for the  achievement  of  business  goals and the
maximization  of  shareholder  returns.  Specific  levels  of pay and  incentive
opportunity are determined by the competitive  market for executive  talent and,
where appropriate,  the need to invest in the future growth of the business. The
compensation  program,  which  provides  incentives  for  executive  officers to
achieve the  short-term  and  long-term  goals of the Company,  comprises  three
components: base salary, incentive compensation and stock option awards.

      BASE SALARY - Base pay levels are largely determined  through  comparisons
      with  service  companies  of similar  size.  Since the  Company's  current
      strategy  places  greater   reliance  on  outstanding   professional   and
      management  skills than on proprietary  technology,  the Company  believes
      that base salaries at the high end of the competitor range may be required
      in certain  circumstances  to maintain the Company's  strategic  position.
      Actual salaries are based on individual performance contributions within a
      tiered  salary range for each  position  that is  established  through job
      evaluation and competitive comparisons.

      MANAGEMENT  INCENTIVE  PLAN  - The  Company's  Management  Incentive  Plan
      provides cash bonus incentives  ("Incentive  Payments") for all management
      employees.  The  bonus  payment  under  this  plan  is  based  on a  fixed
      percentage of an employee's annual salary,  which increases with the grade
      of an employee's position from 10% to a maximum of 40%. This percentage of
      salary  is then  adjusted  to  reflect  the  degree to which  Company  and
      individual  performance  goals are  achieved  (respectively,  the "Company
      Achievement  Percentage" and the "Individual  Achievement  Percentage") by
      multiplying  the  employee's   fixed  bonus   percentage  by  the  Company
      Achievement Percentage and by the Individual Achievement  Percentage.  The
      Company Achievement  Percentage is based on, among other things, sales and
      earnings per share growth.  The  Individual  Achievement  Percentages  for
      executive  officers is based upon the degree to which each officer met the
      individual goals set for him/her, as evaluated by the CEO and Compensation
      Committee.  The  maximum  bonus  attainable  is limited to the  prescribed
      salary  percentage,  unless certain special Company sales and income goals
      are met. Achieving these special "stretch" goals entitles  participants to
      additional compensation equal to 50% of the amount otherwise payable under
      the Management  Incentive Plan ("Extra Incentive  Payout").  Actual awards
      are subject to decrease or increase at the discretion of the Committee. In
      1998, Company performance goals were not achieved.  Therefore,  management
      incentive bonuses were not awarded.

      STOCK OPTION PROGRAM - The Committee  strongly  believes that by providing
      executives  an  opportunity  to own  shares  of  Company  stock,  the best
      interests  of  shareholders   and  executives  will  be  closely  aligned.
      Therefore,  all executives are eligible to receive stock options from time
      to time giving them the right to  purchase  shares of Common  Stock of the
      Company at a specific  price in the  future.  The number of stock  options
      granted to  executive  officers is  determined  at the  discretion  of the
      Committee based on the accomplishments of such executives, their length of
      service  with the  Company,  the number of prior  awards  received by such
      officer,  the relative value as well as the exercise price of such awards,
      and competitive practices.

DISCUSSION OF 1998 COMPENSATION FOR THE CHIEF EXECUTIVE OFFICER

      The  Committee  meets with the Chief  Executive  Officer to  evaluate  his
performance.  For 1998, Mr.  Johnson's  incentive  compensation was based on the
Company  Achievement  Percentage and the  Committee's  evaluation  regarding his
overall  performance based on both quantitative and qualitative  objectives,  as
set by the Board at the start of the year.  While no incentive  compensation was
awarded to Mr.  Johnson in 1998,  during the year Mr.  Johnson  received a stock
grant of 15,000 shares in accordance with the terms of his employment agreement.

      This report has been provided by the  Compensation  Committee of the Board
of Directors:

                                Bruce K. Crowther
                             G. S. Beckwith Gilbert
                           Jeffrey L. Sklar, MD, Ph.D.




                           SUMMARY COMPENSATION TABLE

      The following table sets forth  information  with respect to the following
named executive  officers:  (i) the person who served as Chief Executive Officer
("CEO") during 1998 and (ii) the four most highly compensated executive officers
other than the CEO serving at December 31, 1998 whose total salary and bonus for
1998 exceeded $100,000.

                           SUMMARY COMPENSATION TABLE



                                                                                                Long Term
                                                      Annual Compensation                      Compensation
                                                      -------------------                      ------------
                                                                                 Other          Securities
              Name and                                                           Annual         Underlying       All Other
         Principal Position           Year      Salary       Bonus            Compensation       Options        Compensation
         ------------------           ----      ------       -----            ------------       -------        ------------
                                                                                              
Kevin C. Johnson                     1998      $295,773     $    --              $  --           40,000         $184,599 (1)
President, Chief Executive           1997       281,939      82,378                 --               --          158,360
    Officer and Director             1996       174,520      94,000                 --          200,000            1,507

James B. Amberson, M.D.              1998       239,200          --                 --           12,000           10,568 (2)
Senior Vice President,               1997       238,790      35,451                 --           20,000            2,630
   Chief Medical Officer             1996       200,013      47,869                 --           15,000            2,530
   and Director

David R. Schreiber                   1998       195,582          --                 --           20,000            6,124 (3)
Senior Vice President Finance,       1997       191,170      65,702                 --           20,000          149,167
Chief Financial Officer and          1996        29,231      80,000                 --           50,000            1,742
   Corporate Secretary

Steven T. Clayton                    1998       127,211          --                 --            5,000           43,613 (4)
Vice President, Information          1997       120,000      35,568                 --           15,000           73,073
    Services                         1996         6,923      14,000                 --           15,000               --

John S. Fanuko (5)                   1998       120,046      20,000 (6)             --           30,000               77 (7)
Vice President, Finance              1997            --          --                 --               --               --
    and Corporate Controller         1996            --          --                 --               --               --


(1)   The $184,599  indicated for Mr. Johnson  represents:  (i) a stock grant of
      15,000  shares  of  Common  Stock on  January  2,  1998 at a market  value
      totaling $146,250; (ii) a loan forgiveness aggregating $30,000 pursuant to
      Mr.  Johnson's  employment  agreement;  (iii) an auto allowance of $5,214;
      (iv) contributions of $1,600 paid by the Company pursuant to the Company's
      401(K)  Retirement  Plan; and (v) term life  insurance  premiums of $1,535
      paid by the Company.

(2)   The $10,568  indicated for Dr.  Amberson  represents an auto  allowance of
      $8,028,  contributions  of  $1,600  paid by the  Company  pursuant  to the
      Company's 401(K) Retirement Plan, and term life insurance premiums of $940
      paid by the Company.

(3)   The $6,124  indicated for Mr.  Schreiber  represents an auto  allowance of
      $4,440,  contributions  of  $1,600  paid by the  Company  pursuant  to the
      Company's 401(K)  Retirement Plan and term life insurance  premiums of $84
      paid by the Company.

(4)   The $43,613  indicated  for Mr.  Clayton  represents  relocation  costs of
      $12,267,  a tax  reimbursement  of $31,262 related to relocation costs and
      term life insurance premiums of $84 paid by the Company.

(5)   Mr.  Fanuko  joined the Company in January 1998 as Vice  President-Finance
      and Corporate Controller and resigned from the Company in March 1999.

(6)   The $20,000 indicated  for Mr. Fanuko represents a sign-on bonus.

(7)   The $77 indicated for Mr. Fanuko  represents term life insurance  premiums
      paid by the Company.




PERFORMANCE GRAPH

      The Securities and Exchange  Commission  requires that the Company include
in  this  Proxy  Statement  a  line-graph   presentation   comparing  cumulative
shareholder  return on an indexed  basis with a broad  equity  market  index and
either a published  industry index or an index of peer companies selected by the
Company. The graph below compares the cumulative total return during such period
on $100 invested as of December 31, 1993 in the Common Stock of the Company, the
H&Q Health Care Sub-Sector excluding the Biotechnology Sector of the Hambrecht &
Quist  Technology  and Growth  Indices  and the NASDAQ  National  Market  Index,
assuming the reinvestment of all dividends:

                 COMPARISON OF FIVE-YEAR CUMULATIVE TOTAL RETURN


HAMBRECHT & QUIST INDEX PRODUCTS AND SERVICES:
1999 PROXY PERFORMANCE GRAPH DATA

SCALED PRICES:  Stock and index prices scaled to 100 at 12/31/93

                                 Nasdaq Stock      H&Q Healthcare Excl.
   DATES     DIANON Systems      Market -U.S.            Biotech
   -----     --------------      ------------            -------
   Dec-93        100.00             100.00                100.00
   Dec-94         66.67             106.25                 97.75
   Dec-95         70.83             176.91                138.26
   Dec-96        143.75             196.41                170.11
   Dec-97        156.25             234.07                208.44
   Dec-98        150.00             284.41                293.72

ACTUAL PRICES

                                 Nasdaq Stock      H&Q Healthcare Excl.
   DATES     DIANON Systems      Market -U.S.            Biotech
   -----     --------------      ------------            -------
   Dec-93         6.00             250.008               352.259
   Dec-94         4.00             244.582               374.288
   Dec-95         4.25             345.901               623.196
   Dec-96        8.625             425.440               691.892
   Dec-97        9.375             521.129               824.541
   Dec-98         9.00             734.325               1001.88





EMPLOYMENT AND SEVERANCE AGREEMENTS


      The Company  entered into an employment  agreement with Mr. Johnson on May
2, 1996.  The  agreement  provides for Mr.  Johnson to serve as President of the
Company at an initial base salary of $275,000 per annum, the grant of options to
purchase  200,000  shares of Common  Stock with a 10-year  term and an  exercise
price of $5.69, stock grants of 15,000 shares of Common Stock on January 2, 1997
and 15,000  additional  shares on January 2, 1998 provided Mr. Johnson continues
to be employed  with the Company on such date, a signing  bonus of $50,000 and a
loan of $150,000.  The loan carries an interest rate of 5.9%,  payable annually,
and is repayable upon termination of Mr. Johnson's  employment with the Company.
If Mr.  Johnson  continues to be employed with the Company,  the loan  principal
will be forgiven at the rate of $2,500 per completed  month of  employment  from
January 31, 1998 through December 31, 2002. This agreement  provides that in the
event of a termination of Mr.  Johnson's  employment  other than for "Cause," as
defined in the agreement,  he is entitled to receive one year's salary and other
benefits.  Subject to the foregoing, this agreement is subject to termination at
will by either party.

      The Company  entered into an employment  agreement with David R. Schreiber
on September 30, 1996 as the Chief Financial  Officer and Senior Vice President,
Finance.  The  agreement  provides  for an initial  base salary of $190,000  per
annum,  the grant of options to purchase  50,000  shares of Common  Stock with a
10-year term and an exercise  price of $6.625,  a signing bonus of $80,000 and a
stock grant of 7,500  shares of Common  Stock on April 1, 1997.  This  agreement
provides that in the event of a termination of Mr. Schreiber's  employment other
than for  "Cause,"  as defined in the  agreement,  he is entitled to receive one
year's salary (and certain other benefits) if such termination occurs within the
first year of  employment or six months after the Company is acquired by another
business  entity,  or six month's  salary (and certain  other  benefits) if such
termination occurs after such period.  Subject to the foregoing,  this agreement
is subject to termination at will by either party.

      The  Company  entered  into an  agreement  with Dr.  James B.  Amberson on
September 1, 1996,  which  provides that  following a "Change in Control" of the
Company, as defined in the agreement, if Dr. Amberson's employment is terminated
other than for "Cause," as defined in the  agreement,  he is entitled to receive
one year's salary and bonus and all his stock options will vest completely.  Dr.
Amberson's  agreement  expires in  September  2001 and is subject to  successive
automatic one-year renewals thereafter (unless certain notice is given).

      The Company also entered into an  employment  agreement  with Dr. James B.
Amberson on  September  1, 1996.  Pursuant to such  agreement,  Dr.  Amberson is
entitled to a salary as  determined by the Company and other  employee  benefits
made available by the Company to its employees.  This agreement provides that in
the event of a termination of Dr.  Amberson's  employment for other than "Stated
Cause" (as  defined in the  agreement),  he is  entitled  to receive six month's
salary and other benefits.  Subject to the foregoing,  this agreement is subject
to termination at will by either party.

       The Company  entered into an employment  agreement with Steven T. Clayton
on November 18, 1996 as Vice President, Information Services of the Company. The
agreement  provides for an initial base salary of $120,000 per annum,  a signing
bonus of $14,000  and the grant of options to purchase  15,000  shares of Common
Stock with a 10-year term and an exercise price of $7.875.





CHANGE OF CONTROL PROVISIONS

      As a general  matter,  under the Company's 1996 Stock Incentive Plan, upon
the occurrence of a Change of Control (as defined  below),  (1) all  outstanding
stock options, SARs, and limited SARs, including those held by Outside Directors
(as defined in such plan),  will become fully  exercisable  and vested,  (2) all
other awards under the Plan will become fully vested,  and (3) to the extent the
cash payment of any award is based on the fair market value of stock,  such fair
market value will be the Change of Control Price (as defined below).

      A "Change  of  Control"  is deemed to occur on the date (1) any  person or
group acquires  beneficial  ownership of securities  representing 25% or more of
the Company's total voting power (with certain exceptions),  (2) individuals who
constitute  the "Current  Directors" (as defined in the Plan) fail to constitute
at least two-thirds of the Board of Directors,  (3) the  shareholders  approve a
merger or  consolidation  unless  following such  transaction (a) the beneficial
owners of the  Company's  Common Stock  before the  transaction  own  securities
representing  more than 50% of the total voting  power of the company  resulting
from the  transaction,  and (b) at least a  majority  of members of the board of
directors  of the company  resulting  from the  transaction  were members of the
Company's Board of Directors at the time such Board approved the transaction, or
(4) the shareholders of the Company approve a sale of  substantially  all of its
assets.

      The  "Change of Control  Price" is the  highest  price per share of Common
Stock paid in any open market transaction,  or paid or offered to be paid in any
transaction related to a Change of Control, during the 90-day period ending with
the Change of  Control,  except  that for an SAR  granted in tandem with an ISO,
such price is the highest price paid on the date the SAR is exercised.

      The 1991 Stock  Incentive Plan and the proposed 1999 Stock  Incentive Plan
contain  change of  control  provisions  generally  comparable  to the change of
control  provisions  contained in the Company's  1996 Stock  Incentive  Plan, as
described above.

SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

      Section  16(a)  of the  Securities  Exchange  Act  of  1934  requires  the
Company's  directors and executive  officers,  and persons who own more than ten
percent of a registered class of the Company's equity  securities,  to file with
the Securities and Exchange  Commission initial reports of ownership and reports
of changes in  ownership  of Common  Stock and other  equity  securities  of the
Company.  Officers,  directors  and greater  than ten percent  shareholders  are
required  to furnish the  Company  with  copies of all Section  16(a) forms they
file.

      To the Company's  knowledge,  based solely on review of the copies of such
reports furnished to the Company and representations  that no other reports were
required  during the fiscal year ended  December  31,  1998,  all Section  16(a)
reporting  requirements  applicable to its officers,  directors and greater than
ten percent beneficial shareholders were complied with except for the following:
Mr.  Stefanelli  was late in filing his initial Form 3 when becoming  subject to
the Section 16 reporting  requirements,  and Messrs.  Verfurth and Sandberg each
filed a late report with respect to one transaction.





STOCK OPTIONS

      The  following  table  shows,  as to the named  executive  officers of the
Company,  information  about option grants in the last fiscal year. The Company,
as of  September  8, 1999,  has not  granted  any Stock  Appreciation  Rights to
officers.



                                       INDIVIDUAL GRANTS
- ------------------------------------------------------------------------------------------------
                                                                                                   POTENTIAL REALIZABLE
                                                                                                     VALUE AT ASSUMED
                                   NUMBER OF            % OF TOTAL                                ANNUAL RATES OF STOCK
                                  SECURITIES              OPTIONS                                   PRICE APPRECIATION
                                  UNDERLYING            GRANTED TO    EXERCISE OR                    FOR OPTION TERM
                                    OPTIONS              EMPLOYEES     BASE PRICE    EXPIRATION   ---------------------
            NAME                  GRANTED(#)              IN 1998      ($/SHARE)        DATE        5%($)       10%($)
            ----                  ----------              -------      ---------        ----        -----       ------
                                                                                             
James B. Amberson, M.D.               12,000  (2)             5%        $6.875       10/28/2008     $51,884    $131,484
Steven T. Clayton                      5,000  (2)             2%         6.875       10/28/2008      21,618      54,785
John S. Fanuko                        15,000  (1)             6%         8.750       01/09/2008      82,542     209,179
John S. Fanuko                        15,000  (2)             6%         6.875       10/28/2008      64,855     164,355
Kevin C. Johnson                      40,000  (2)            16%         6.875       10/28/2008     172,946     438,279
David R. Schreiber                    20,000  (2)             8%         6.875       10/28/2008      86,473     219,140


(1)   In January  1998,  the  Company  granted  Mr.  John S.  Fanuko  options to
      purchase  15,000  shares of Common Stock at $8.75 per share when he joined
      the  Company.  These  options vest 40% in January 2000 and 20% during each
      year thereafter. Upon termination,  all unvested options are cancelled and
      all vested options expire 90 days after termination of employment.
(2)   In October  1998,  the Company  granted  certain  employees  and  officers
      options to purchase  217,000  shares of Common  Stock at $6.875 per share.
      These  options  vest  40%  in  October  2000  and  20%  during  each  year
      thereafter.  Upon termination,  all unvested options are cancelled and all
      vested options expire 90 days after termination of employment.





        The following table shows aggregate  option exercises in the last fiscal
year and fiscal  year-end option values for the named  executive  officers.  The
Company,  as of September 8, 1999, has not granted any Stock Appreciation Rights
to officers.


    AGGREGATED OPTION EXERCISES IN LAST FISCAL YEAR AND FY-END OPTION VALUES



                                               VALUE
                                               REALIZED
                                               (MARKET                                            VALUE OF UNEXERCISED
                                               PRICE AT         NUMBER OF SECURITIES         IN-THE-MONEY OPTIONS AT FY-END
                                               EXERCISE    UNDERLYING UNEXERCISED OPTIONS      (BASED ON FY-END PRICE OF
                                   SHARES      LESS                 AT FY-END(#)                  $9.00/SHARE) ($) (1)
                                ACQUIRED ON    EXERCISE             ------------                  --------------------
            NAME                EXERCISE(#)    PRICE)($)    EXERCISABLE    UNEXERCISABLE     EXERCISABLE     UNEXERCISABLE
            ----                -----------    ---------    -----------    -------------     -----------     -------------
                                                                                           
James B. Amberson, M.D.                  --         $ --         46,300           57,200        $189,777          $113,708
Steven T. Clayton                        --           --          6,000           29,000           6,750            24,500
John S. Fanuko                           --           --              0           30,000               0            35,625
Kevin C. Johnson                         --           --         80,000          160,000         265,000           482,500
David R. Schreiber                       --           --         20,000           70,000          47,500           118,750


(1)  Computed  based upon  difference  between  aggregate  fair market value and
     aggregate exercise price.



           COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION

      Dr.  Sklar  served  as a  member  of  the  Compensation  Committee  of the
Company's  Board of  Directors  during  the last  completed  fiscal  year and is
continuing to serve as such in the 1999 fiscal year. In 1995 the Company entered
into a three-year  research  and  development  agreement  with Brigham & Women's
Hospital,  Inc.,  for  which  Dr.  Sklar is  director,  Division  of  Diagnostic
Molecular Biology,  Department of Pathology.  The agreement required the Company
to make quarterly payments of $30,000 in exchange for an option to obtain rights
in certain existing inventions as well as inventions developed during the course
of the research in the areas of cancer detection and diagnosis. The research was
to be conducted by Dr.  Sklar.  The Company paid $8,000,  $60,000,  $120,000 and
$60,000 under this agreement in 1998,  1997,  1996 and 1995,  respectively.  The
Company terminated this agreement effective as of June 30, 1997 and has made all
required payments.  In addition,  the Company made payments to Brigham & Women's
Hospital, Inc. of $30,000 in 1996 for consulting services.




                     OWNERSHIP OF VOTING STOCK BY MANAGEMENT

       The following table gives information concerning the beneficial ownership
of the Company's  Common Stock as of September 8, 1999 by each director and each
of the  executive  officers  named in the  summary  compensation  table  and all
current directors and executive officers (as of September 8, 1999) as a group.



                                                  Total Shares
                                                  Beneficially        Direct         Right to      Percent of
Beneficial Owners                                 Owned(1)(2)        Ownership      Acquire(3)      Class(4)
- -----------------                                 -----------        ---------      ----------      --------
                                                                                        
James B. Amberson, M.D.                               113,336           31,402          59,000          1.7%
Steven T. Clayton                                       6,000               --           6,000            --  (5)
Bruce K. Crowther                                       3,629            1,610           2,019            --  (5)
John P. Davis                                         244,245          118,739         125,506          3.5%
John S. Fanuko                                             --               --              --            --  (5)
E. Timothy Geary                                        5,101            2,056           3,045            --  (5)
G. S. Beckwith Gilbert                              1,811,022        1,802,519           8,503         26.5%  (6)
Kevin C. Johnson                                      173,677           30,743         120,000          2.5%
David R. Schreiber                                     61,117            8,183          30,000            --  (5)
Jeffrey L. Sklar, M.D., Ph.D.                          21,941            2,519          19,422            --  (5)

All current directors and executive officers
   as a group (11 persons)                          2,410,699        1,997,822         389,943         33.5%



(1)  The information as to beneficial ownership is based on statements furnished
     to the Company by its  executive  officers and  directors.  Each  executive
     officer and director has sole voting and sole investment power with respect
     to his respective shares listed above,  except that the shares reported for
     Mr. Gilbert  include  121,951 shares which are held by a trust of which Mr.
     Gilbert is a trustee,  as to which Mr. Gilbert shares voting and investment
     powers.  Amounts  shown for each of Messrs.  Johnson and  Schreiber and Dr.
     Amberson  include  22,934  shares held in the Company's  401(K)  Retirement
     Plan, as to which such officers share voting power as trustees of such plan
     and each individual plan participant has investment  power,  subject to the
     terms of such plan, of the shares in his account;  such amount includes 743
     shares in Mr. Johnson's account and 683 shares in Mr. Schreiber's account.
(2)  Includes shares listed under the captions "Direct  Ownership" and "Right to
     Acquire," as well as shares held in the Company's  401(K)  Retirement  Plan
     which are beneficially  owned by the named  individuals as trustees of such
     plan but as to which such trustees have no economic interest.
(3)  Individuals  have the  right to  acquire  these  shares  within  60 days of
     September  8, 1999 by the  exercise of stock  options or through  purchases
     under the Company's Employee Stock Purchase Plan.
(4)  For the purposes of this table,  "Percent of Class" held by each individual
     has  been  calculated  based  on a  total  class  equal  to the  sum of (i)
     6,814,967  shares of Common  Stock issued and  outstanding  on September 8,
     1999 plus (ii) for such  individual  the  number of shares of Common  Stock
     subject to stock options presently  exercisable,  or exercisable  within 60
     days after September 8, 1999, held by that individual, and which percent is
     rounded to the nearest tenth.
(5)  Owns less than 1% of the outstanding Common Stock.
(6)  As of September 8, 1999, Mr. Gilbert cannot vote, without restriction,  any
     Common Stock or other voting securities of the Company  beneficially  owned
     by him  representing  greater  than 20% of the  total  voting  power of the
     Company's  voting  securities  outstanding  from time to time, or 1,362,993
     votes as of September 8, 1999.  Excess votes above this amount are required
     to be voted in  proportion to the votes cast by all other  shareholders  of
     the Company.




             OWNERSHIP OF VOTING STOCK BY CERTAIN BENEFICIAL OWNERS

       The  following  table sets  forth  information  with  respect to the only
persons who, to the best knowledge of the Company as derived from Schedules 13F,
13D and 13G filed by such persons,  beneficially owned more than five percent of
the Common  Stock of the  Company as of  September  8,  1999.  Unless  otherwise
indicated  below,  each  person  included  in the  table  has  sole  voting  and
investment power with respect to all shares included therein.



                                                                   Amount and Nature
                                 Name and Address of                 of Beneficial          Percent
   Title of Class                 Beneficial Owner                      Ownership         of Class(1)
   --------------                 ----------------                      ---------         -----------
                                                                                 
Common Stock          G. S. Beckwith Gilbert et al                   1,811,022  (2) (3)   26.5%   (3)
                      104 Field Point Road
                      Greenwich, CT 06830

Common Stock          Oracle Management Partners, Inc.                 728,300            10.7%
                      and Affiliates
                      712 E 5th Avenue - 45th Floor
                      New York, NY  10019

Common Stock          John M. Bryan et al                              356,412             5.2%
                      Bryan and Edwards
                      600 Montgomery Street - 35th Floor
                      San Francisco, CA  94111


(1)  For the purposes of this table,  "Percent of Class" held by each person has
     been  calculated  based on a total class equal to the sum of (i)  6,814,967
     shares of Common  Stock  issued and  outstanding  on September 8, 1999 plus
     (ii) for such person the number of shares of Common Stock  subject to stock
     options or warrants  presently  exercisable,  or exercisable within 60 days
     after September 8, 1999, held by that person,  and which percent is rounded
     to the nearest tenth.
(2)  Mr. Gilbert has shared voting and investment  power with respect to 121,951
     shares included in the table above.
(3)  As of September 8, 1999, Mr. Gilbert cannot vote, without restriction,  any
     Common Stock or other voting securities of the Company  beneficially  owned
     by him  representing  greater  than 20% of the  total  voting  power of the
     Company's  voting  securities  outstanding  from time to time, or 1,362,993
     votes as of September 8, 1999.  Excess votes above this amount are required
     to be voted in  proportion to the votes cast by all other  shareholders  of
     the Company.


                  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

      See "Compensation Committee Interlocks and Insider Participation" section.

      Pursuant  to his  employment  agreement,  the  President  of  the  Company
received a loan in 1996 totaling $150,000 which bears interest at 5.9%,  payable
annually,  and is repayable upon termination of his employment with the Company.
In addition,  the loan  principal will be forgiven at a rate of $2,500 per month
over the period January 1998 through December 2002 if the President continues to
be employed by the Company.



                  ADOPTION OF THE EMPLOYEE STOCK PURCHASE PLAN

      The Board of  Directors  has  adopted,  subject to  approval at the Annual
Meeting, the Dianon Systems, Inc. Employee Stock Purchase Plan (the "Plan"). The
purpose of the Plan is to encourage  employees to acquire an ownership  interest
in the Company in order to further link the interests of the Company's employees
with those of its shareholders.

PRINCIPAL PROVISIONS OF THE PLAN

      The  following  summary of the Plan,  as adopted by the Board of Directors
subject to shareholder  approval,  is qualified by reference to the full text of
the Plan, which is attached as Exhibit A to this Proxy Statement.

GENERAL PROVISIONS OF THE PLAN

      The Company has reserved a maximum of 300,000 shares of Common Stock to be
sold to employees  under the Employee  Stock Purchase Plan. No more than 100,000
shares of Common  Stock will be  available  for  purchase  under the Plan in any
calendar year and no participating employee may purchase more than 500 shares of
Common  Stock in any  calendar  quarter,  which is referred to in the Plan as an
"Offering  Period."  Subject  to the  approval  of  the  Plan  by the  Company's
shareholders,  the first  Offering  Period will commence on January 1, 2000. The
shares to be offered for sale to  participating  employees under the Plan may be
authorized but previously  unissued  shares,  shares held in or acquired for the
Company's treasury or shares reacquired by the Company in open market purchases.

      The Plan will be  administered  by a committee of the Board of  Directors,
consisting of at least two outside directors serving on the Board. The Committee
will have the general  authority to interpret the  provisions of the Plan and to
adopt such rules as it deems  necessary or desirable for the  administration  of
the Plan. It is anticipated  that the Committee will appoint a senior  executive
officer of the Company to handle the day-to-day  administration  of the Plan and
to serve as the "Plan Administrator."

ELIGIBILITY AND PARTICIPATION IN THE PLAN

      All employees of the Company (other than 5% shareholders)  are eligible to
participate in the Plan if they customarily work a minimum of 20 hours per week,
at least five  months  each  year.  Outside  directors  of the  Company  are not
eligible to participate in the Plan. In addition, any employee holding an option
under the Plan (and any other employee stock purchase plan of the Company or its
affiliates) which provides for him to purchase more than $25,000 worth of Common
Stock in any calendar year will not be eligible to participate in the Plan.

      An  eligible  employee  may elect to  participate  in the Plan by filing a
payroll deduction  authorization  election,  together with all other appropriate
enrollment forms, with the Plan Administrator prior to the first day an Offering
Period  commences.  An  employee  may  authorize  the  Company  to make  payroll
deductions in whole percentages of his annual compensation on an after-tax basis
(excluding  bonuses  and  incentive  pay) not to exceed the lesser of 10% of his
base pay or $5,000  annually.  The Company will establish a separate  memorandum
account for each employee for purposes of recording the payroll  deductions made
by the  employee  during  an  Offering  Period.  These  accounts  will  not bear
interest.  Payroll  deductions  made by an  employee in excess of $5,000 will be
refunded  to the  participant,  without  interest,  at the  end of the  Offering
Period.

      On the last day of each  Offering  Period,  referred to in the Plan as the
"Exercise Date," the payroll deductions that have accumulated in a participating
employee's  memorandum  account will automatically be used to purchase shares of
Common  Stock up to the 500  share  maximum  established  under  the  Plan.  The
purchase  price for these shares will be 85% of the fair market value of a share
of Common  Stock on the  Exercise  Date.  Any  surplus  funds  remaining  in the
participant's memorandum account after the shares are purchased will be returned
to the participant,  without interest. The Company will arrange for the delivery
of shares purchased by an employee under the Plan.

      An  employee  may  withdraw  from  participation  in the Plan prior to the
Exercise Date. If an employee  withdraws from the Plan, his accumulated  payroll
deductions will be returned to him, without interest.  If the employee wishes to
resume  participation  in the Plan, he will be required to complete and file the
appropriate  payroll deduction and enrollment forms with the Plan  Administrator
prior to the first day of the next Offering Period.

      In the event a participating  employee dies prior to the Exercise Date for
an Offering  Period,  all funds credited to the deceased  employee's  memorandum
account  will  be  returned,   without  interest,  to  the  deceased  employee's
designated beneficiary or his estate, as applicable.

AMENDMENT, TERMINATION AND SUSPENSION OF THE PLAN

      The Board may amend, suspend or discontinue the Plan at any time; however,
the Board may not take any action  which would cause the Plan not to comply with
Section 423 of the Code, or any successor rules, or that would change the number
of shares  reserved for purchase under the Plan (other than due to stock splits,
stock  dividends or other such events).  The Plan will  automatically  terminate
upon the adoption by the Board of a resolution  terminating the Plan or upon the
sale of the maximum  number of shares of Common  Stock  available  for  purchase
under the Plan.

FEDERAL INCOME TAX CONSEQUENCES

      The  following  is a summary of certain  federal  income tax  consequences
triggered upon the purchase of Common Stock under the Plan,  based upon the laws
in effect on the date hereof.  All  references  to the "Code" are  references to
provisions of the Internal Revenue Code of 1986, now in effect.

      The Employee  Stock  Purchase  Plan is intended to qualify as an "employee
stock purchase plan" within the meaning of Section 423 of the Code. As a result,
an employee  will not  realize  income for  federal  income tax  purposes on the
applicable  Exercise  Date when shares of Common Stock are  purchased  under the
Plan. Instead,  assuming the 2-year holding period requirement (described below)
is  satisfied,  the  gain  recognized  by the  employee  on the  sale  or  other
disposition  of the Common Stock will be taxed as long-term  capital  gain.  Any
loss on the sale or other  disposition  of the  Common  Stock will be treated as
long-term  capital loss. To meet the holding period  requirement under the Code,
an employee must not sell or otherwise dispose of the shares of the Common Stock
acquired under the Plan until at least two years after the date of purchase.

      If an employee sells or otherwise  disposes of the Common Stock within two
years after the date of purchase,  the employee will  recognize as  compensation
income  the full  amount of the  excess of the fair  market  value of the Common
Stock on the date of  purchase  over the  amount  paid by the  employee  for the
Common Stock.  Any additional gain realized on the sale or other  disposition of
the Common Stock will be taxed as capital  gain,  which will be long-term if the
employee has held the Common Stock for more than one year,  and any loss will be
a capital loss.

      The Company will be entitled to a deduction for the amount of compensation
income  recognized by an employee who sells or otherwise  disposes of the Common
Stock  within two years  after the date of  purchase.  The  Company  will not be
entitled to a deduction for any capital gain recognized by an employee who holds
the Common Stock for at least two years after the date of purchase.

      THE COMPANY'S BOARD OF DIRECTORS  RECOMMENDS THAT  SHAREHOLDERS VOTE "FOR"
APPROVAL OF THE EMPLOYEE STOCK PURCHASE PLAN. Approval of the Plan requires that
the votes cast in favor of approval  of the Plan  exceed the votes cast  against
such  approval.  Pursuant  to  the  Company's  Bylaws,  abstentions  and  broker
"non-votes"  (shares not voted because a nominee holding shares for a beneficial
owner neither  receives voting  instructions  from the beneficial  owner nor has
discretionary  voting  power with  respect  thereto)  will have no effect on the
vote.



                    ADOPTION OF THE 1999 STOCK INCENTIVE PLAN

      The Board of  Directors  has  adopted,  subject to  approval at the Annual
Meeting,  the Dianon Systems,  Inc. 1999 Stock Incentive Plan (the "Plan").  The
purposes of the Plan are to enable the Company to attract, retain and reward key
employees and outside  directors by providing such  individuals  with equity and
equity-based long-term incentive compensation awards.

PRINCIPAL PROVISIONS OF THE PLAN

      The  following  summary of the Plan,  as adopted by the Board of Directors
subject to shareholder  approval,  is qualified by reference to the full text of
the Plan, which is attached as Exhibit B to this Proxy Statement.

GENERAL PROVISIONS

      The Plan  authorizes the granting of awards in the form of any combination
(independent  or in tandem) of (1) options to purchase  shares of Common  Stock,
(2) stock  appreciation  rights ("SARs"),  (3) shares of restricted Common Stock
("restricted  stock"),  (4) shares of deferred Common Stock ("deferred  stock"),
(5) bonus stock, (6) loans,  and (7) tax-offset  payments with respect to any of
such awards.  Awards may be granted (i) to key employees (including officers) of
the Company and certain  related  companies  by the Plan  Committee  (as defined
below),  and (ii) to directors  who are not employees or officers of the Company
or certain related  companies  ("Outside  Directors") by the Board of Directors.
The Plan also  provides  for the  automatic  grant to Outside  Directors  of (1)
options to  purchase  shares of Common  Stock and related  limited  SARs and (2)
stock grants.

      Administration.  The Plan is  administered  by the Board of Directors with
respect to awards to Outside  Directors,  and by a  committee  of the  Company's
Board of Directors,  which consists of at least two Outside Directors (the "Plan
Committee"),  with respect to awards to  employees.  (The Board of Directors and
the Plan Committee,  in their respective roles, are referred to as the "Granting
Authority.")  With  respect to awards  within  its  jurisdiction,  the  Granting
Authority  designates the persons to be granted awards from among those eligible
and the type and amount of awards to be granted and has  authority  to interpret
the Plan, adopt, alter and repeal administrative regulations,  and determine and
amend the terms of awards.  The Plan  Committee  may delegate to officers of the
Company any of its  authority  under the Plan (other than with respect to awards
to persons  subject to Section 16 of the  Securities  Exchange  Act of 1934,  as
amended, and Performance Awards (as defined below)).

      Eligibility.  The Plan  Committee  may make  awards  under the Plan to key
employees  (including  officers)  of the  Company  or of any entity in which the
Company  owns  at  least  a 20%  interest.  The  Plan  Committee,  in  its  sole
discretion,  will select the key employees  eligible to participate in the Plan.
Outside  Directors are  automatically  granted stock options and related limited
SARs and stock grants having the terms specified in the Plan, and may be granted
discretionary  awards by the Board of Directors.  All key  employees  (currently
numbering  approximately 30) and Outside Directors  (currently  numbering 5) are
eligible to receive awards under the Plan.

      Limitations  on Awards.  The  aggregate  number of shares of Common  Stock
which may be issued under the Plan is 300,000, of which 270,000 may be issued to
key  employees  and 30,000 may be issued to Outside  Directors.  Such shares may
consist of authorized but unissued shares or treasury shares.  The exercise of a
SAR for cash or the settlement of any other award in cash will not count against
this share  limit.  Shares  subject to lapsed,  forfeited  or  canceled  awards,
including  options  canceled upon the exercise of tandem SARs for cash, will not
count  against this limit and can be regranted  under the Plan.  If the exercise
price of an option  is paid in  Common  Stock or if  shares  are  withheld  from
payment of an award to satisfy tax obligations  with respect to the award,  such
shares also will not count against the above limit.

      No key employee may be granted  stock  options,  SARs,  restricted  stock,
deferred  stock,  or bonus stock under the Plan with respect to more than 40,000
shares of Common Stock in any fiscal year.  The Plan does not limit awards which
may be made under other plans of the Company.

DISCRETIONARY AWARDS

      The  Plan  authorizes  the  Granting   Authority  to  grant,   within  its
jurisdiction, the following types of awards in its discretion:

      1. Stock Options.  The Granting Authority is authorized to grant incentive
stock options ("ISOs") and  non-qualified  stock options to purchase such number
of shares of Common Stock as the Granting Authority  determines.  An option will
be  exercisable  at such  times,  over such term and  subject  to such terms and
conditions  as the  Granting  Authority  determines,  and at an  exercise  price
determined  by the  Granting  Authority,  which may be less than the fair market
value of the  Common  Stock at the  date of  grant  of the  option.  ISOs may be
granted only to key employees and are subject to additional  restrictions  as to
exercise  period and exercise price as required by the Internal  Revenue Code of
1986, as amended (the "Code"). Payment of the exercise price of an option may be
made in such manner as the  Granting  Authority  may  provide,  including  cash,
delivery of shares of Common Stock already owned for six months or subject to an
award under the Plan,  "cashless exercise" (an arrangement with a brokerage firm
whereby  shares  issuable upon exercise of an option would be sold by the broker
and the  proceeds  used to pay  the  exercise  price),  or in any  other  manner
specified  by  the  Granting  Authority.  Under  this  provision,  the  Granting
Authority  could  permit  payment  to be  made by way of  successive,  automatic
applications  of shares  received  upon  exercise  of a portion of the option to
satisfy the  exercise  price for  additional  portions of the option,  a payment
method known as "pyramiding".

      The Granting  Authority is authorized to specify the period,  if any, over
which options  become  exercisable,  and to  accelerate  the  exercisability  of
options  on a case by case basis at any time.  The  Granting  Authority  is also
authorized to specify the period during which options may be exercised following
an option holder's  termination of service with the Company,  and to extend such
period on a case by case basis.  The Granting  Authority may permit an option to
be exercised for an additional  period after the option holder's death,  even if
such period extends beyond the original option term.  Unless otherwise  provided
by the Granting Authority, options will not be transferable except by will or by
the laws of  descent  and  distribution.

      2. Stock Appreciation  Rights.  Upon exercise of a SAR the award holder is
entitled to receive,  for each share with respect to which the SAR is exercised,
an amount (the "appreciation") equal to the excess of the fair market value of a
share of Common Stock on the exercise  date over an "amount"  determined  by the
Granting  Authority.  The  appreciation  is payable in cash,  Common Stock, or a
combination of both, as determined by the Granting Authority.

      The  Granting   Authority  may  also  grant  limited  SARs  that  will  be
exercisable  only during the 60-day  period  following a "Change of Control" (as
defined  below) of the Company.  The Granting  Authority may provide that in the
event of a Change of Control,  SARs or limited  SARs may be settled on the basis
of the "Change of Control Price" (as defined below).

      3.  Restricted  Stock.  The  Granting  Authority  is  authorized  to award
restricted stock subject to such terms and conditions as the Granting  Authority
may determine in its sole  discretion.  The Granting  Authority has authority to
determine the number of shares of restricted stock to be awarded,  the price, if
any, to be paid by the recipient of the restricted  stock, and the date or dates
on which the restricted  stock will vest. The vesting of restricted stock may be
conditioned  upon the  completion  of a  specified  period of  service  with the
Company,  upon the attainment of specified performance goals, or upon such other
criteria as the Granting  Authority may  determine.  The Plan gives the Granting
Authority  discretion to accelerate the vesting of restricted stock on a case by
case basis at any time.  The Granting  Authority also has authority to determine
whether the award holder will have the right to vote and/or receive dividends on
shares of restricted stock, and whether the certificates for such shares will be
held by the Company or delivered to the award holder bearing legends to restrict
their transfer.

      Stock  certificates  representing  the restricted  stock granted under the
Plan  will be  registered  in the  award  holder's  name.  However,  no share of
restricted  stock may be sold,  transferred,  assigned  or  pledged by the award
holder  until  such  share  has  vested  in  accordance  with  the  terms of the
restricted stock award. In the event of an award holder's termination of service
before all of his restricted stock has vested,  or in the event other conditions
to the vesting of restricted stock have not been satisfied prior to any deadline
for the  satisfaction of such  conditions set forth in the award,  the shares of
restricted  stock which have not vested will be forfeited and any purchase price
paid by the award holder generally will be returned to the award holder.  At the
time  restricted  stock  vests,  a  certificate  for such vested  shares will be
delivered  to the  award  holder  (or the  beneficiary  designated  by the award
holder,  in the event of death),  free of all  restrictions.

      4. Deferred Stock.  Deferred stock may be conditioned  upon the attainment
of specific  performance goals or such other criteria as the Granting  Authority
may determine.  In making an award of deferred stock the Granting Authority will
determine the periods,  if any, during which the award is subject to forfeiture,
and may provide for the issuance of stock pursuant to the award without  payment
therefor.  Upon  vesting,  the award will be settled in shares of Common  Stock,
cash equal to the fair market value of such stock, or a combination  thereof, as
provided  by the  Granting  Authority.  During  the  deferral  period set by the
Granting Authority,  the award holder may not sell,  transfer,  pledge or assign
the deferred  stock award.  In the event of  termination  of service  before the
expiration of the deferral  period,  the deferred stock award will be forfeited,
except as may be provided by the Granting  Authority.  Deferred stock will carry
no voting rights until such time as the Common Stock is actually issued.

      5. Bonus Stock.  The Granting  Authority  may award bonus stock subject to
such terms and  conditions as it may  determine.  Such awards may be conditioned
upon  attainment  of specific  performance  goals or such other  criteria as the
Granting  Authority  may  determine,  and the Granting  Authority may waive such
conditions  in its  discretion.  Bonus  stock  may  be  issued  without  payment
therefore or may be sold at a discount from its fair market value.

      6. Loans.  The Granting  Authority may provide that the Company will make,
or arrange for, a loan with respect to the exercise of any stock option  granted
under the Plan,  with respect to the payment of the purchase  price,  if any, of
any restricted  stock awarded under the Plan, and / or with respect to any taxes
arising  from an award under the Plan,  provided  that the Company will not loan
more than the sum of (i) the  excess of the  purchase  or  exercise  price of an
award  over the par value of any  shares  awarded,  plus (ii) the  amount of any
taxes arising from such award.  The Granting  Authority will determine the terms
of any such loan.

      7. Tax-Offset  Payments.  The Granting  Authority is authorized to provide
for a tax-offset  payment by the Company to an award holder not in excess of the
amount necessary to pay the federal,  state, local, and other taxes payable with
respect to any award and the receipt of the  tax-offset  payment,  assuming  the
award holder is taxed at the maximum tax rate applicable to such income.  Due to
variations in the actual tax rates  applicable to award holders,  the benefit of
the  tax-offset  payment may not  correspond  to the actual tax liability of the
award holder. Tax-offset payments are payable in cash.

      8.  Performance  Awards.  The Plan  Committee  can designate any awards to
employees  under the Plan as  "Performance  Awards",  and the Plan provides that
awards so  designated  are to be granted  and  administered  so as to qualify as
"performance-based  compensation" under Section 162(m) of the Code. The grant or
vesting of a Performance Award will be subject to the achievement of performance
objectives  (the  "Performance  Objectives")  established  by the Plan Committee
based on one or more of the  following  criteria,  which the Plan  Committee may
apply to the Company on a  consolidated  basis  and/or to a business  unit,  and
which the Plan  Committee may use either as an absolute  measure or as a measure
of  comparative  performance  relative  to a peer  group  of  companies:  sales,
operating  profits,  operating  profits before interest  expense and taxes,  net
earnings,  earnings  per share,  return on equity,  return on assets,  return on
invested  capital,  total shareholder  return,  cash flow, debt to equity ratio,
market share, stock price, economic value added, and market value added.

      The  Performance  Objectives  for a particular  Performance  Award must be
established  by the Plan  Committee  in  writing no later than 90 days after the
beginning of the Company's  fiscal year to which it relates.  The Plan Committee
has authority to determine  whether the  Performance  Objectives and other terms
and conditions of the award are satisfied, but has discretion to modify or waive
the  Performance  Objectives  or  conditions  to  the  grant  or  vesting  of  a
Performance  Award only to the extent that the exercise of such discretion would
not  cause  the  Performance  Award  to fail to  qualify  as  "performance-based
compensation"  within the meaning of Section  162(m) of the Code.

      9. Deferral of Awards.  The Granting  Authority may permit an award holder
to defer receipt of any award for a specified period or until a specified event.

AUTOMATIC AWARDS TO OUTSIDE DIRECTORS

      The Plan  provides  for the  automatic  grant of stock  options  and stock
grants to Outside  Directors  on the  following  terms.  Each  person who was an
Outside  Director  on August  31,  1999,  the date this Plan was  adopted by the
Company's  Board of Directors,  and each person who becomes an Outside  Director
after such date will be granted on the date of his or her initial  election  (or
the first  trading day  thereafter),  an option to purchase  the number of whole
shares of Common Stock  obtained by dividing  $5,000 by the closing price of the
Common  Stock on the date of grant.  On the first  trading day of each  calendar
quarter  beginning with October 1, 1999,  each Outside  Director then serving on
the Board of  Directors  and who has served for all or a portion of the previous
calendar  quarter  will be  granted  an option to  purchase  the number of whole
shares of Common Stock  obtained by dividing  $5,000 by the closing price of the
Common Stock on the date of grant.

      The option price of all options automatically granted to Outside Directors
will be equal to the closing  sales price of a share of Common Stock on the date
of option  grant,  and may be paid using cash or Common Stock owned for at least
six months,  or a combination  thereof,  in the discretion of the option holder.
Each option has a ten-year term, and vests with respect to 10% of the underlying
shares three months after the date of grant, and an additional 10% at the end of
each three-month period  thereafter,  assuming continued service on the Board of
Directors.  The minimum  number of shares with respect to which an option may be
exercised  at any time is the  lesser  of 100  shares  or the  number  of shares
subject to the option.  Following an Outside Director's  termination of service,
the options which have previously become exercisable will remain exercisable for
five years after such termination, but not beyond their 10-year term.

      An option  shall only be  exercisable  by the option  holder or his or her
guardian or legal  representative.  No holder of an option shall have any of the
rights of a shareholder.

      Each  automatic  option to Outside  Directors  is granted in tandem with a
limited SAR which may be  exercised  only within the 60-day  period  following a
Change of Control.  Upon exercise of the limited SAR, the  appreciation  will be
paid in cash based on the Change of Control Price.

      On the first trading day of each calendar quarter beginning with the first
calendar  quarter  after the date of  shareholder  approval  of the  Plan,  each
Outside  Director  then serving on the Board of Directors and who has served for
all or a portion of the previous calendar quarter will be automatically  granted
the number of whole  shares of Common Stock  obtained by dividing  $2,000 by the
closing  price of the Common  Stock on the date of grant.  No cash is payable by
the Outside  Director  for such  shares.  Such  shares will be fully  vested and
non-forfeitable at the time of grant.

PROVISIONS RELATING TO A CHANGE OF CONTROL

      As a general  matter,  upon the  occurrence of a Change of Control (1) all
outstanding  stock  options,  SARs,  and limited SARs,  including  those held by
Outside   Directors,   will  become  fully  exercisable  and  vested,   (2)  all
restrictions and deferral limitations applicable to outstanding restricted stock
and deferred stock awards under the Plan will lapse,  and such shares and awards
will be deemed fully vested, and (3) to the extent the cash payment of any award
is based on the fair market  value of stock,  such fair market value will be the
Change of Control Price.

      A "Change  of  Control"  is deemed to occur on the date (1) any  person or
group acquires  beneficial  ownership of securities  representing 25% or more of
the Company's total voting power (with certain exceptions),  (2) individuals who
constitute  the "Current  Directors" (as defined in the Plan) fail to constitute
at least two-thirds of the Board of Directors,  (3) the  shareholders  approve a
merger or  consolidation  unless  following such  transaction (a) the beneficial
owners of the  Company's  Common Stock  before the  transaction  own  securities
representing  more than 50% of the total voting  power of the company  resulting
from the  transaction,  and (b) at least a  majority  of members of the Board of
Directors  of the Company  resulting  from the  transaction  were members of the
Company's Board of Directors at the time such Board approved the transaction, or
(4) the shareholders of the Company approve a sale of  substantially  all of its
assets.

      The  "Change of Control  Price" is the  highest  price per share of Common
Stock paid in any open market transaction,  or paid or offered to be paid in any
transaction  related to a Change of Control during the 90-day period ending with
the Change of Control, except that for a SAR granted in tandem with an ISO, such
price is the highest price paid on the date the SAR is exercised.

OTHER PROVISIONS

      Tax Withholding. The Plan permits employees to satisfy all or a portion of
their  federal,  state,  local or other tax  liabilities  with respect to awards
under the Plan by  delivering  previously-owned  shares (that have been owned by
the optionee for at least six months) or by having the Company withhold from the
shares otherwise deliverable to such employee shares having a value equal to the
tax liability to be so satisfied.

      Adjustments.  In the event of specified  changes in the Company's  capital
structure,  the Plan Committee will have the power to adjust the number and kind
of shares  authorized  by the Plan  (including  any  limitations  on  individual
awards),  the  number of stock  options to be  automatically  granted to Outside
Directors,  and the  number,  option  price  and  kinds  of  shares  covered  by
outstanding awards (including those held by Outside Directors), and to make such
other  adjustments  in awards under the Plan as it deems  appropriate,  provided
that no such adjustment may increase the aggregate value of outstanding awards.

      Amendments.  The Board of Directors may amend the Plan without shareholder
approval,   unless  such  approval  is  required  by  law  or  other  regulatory
requirements.  Amendment or  discontinuation of the Plan cannot adversely affect
any award previously granted without the award holder's written consent.

      The  Granting  Authority  may amend any grant  under the Plan  within  its
jurisdiction  (including  both  discretionary  and  automatic  grants to Outside
Directors) to include any provision  which,  at the time of such  amendment,  is
authorized under the terms of the Plan,  except that no award can be modified in
a manner  unfavorable  to the award  holder  without the written  consent of the
award holder.  In addition,  the Granting  Authority  may,  without  shareholder
approval, cancel an option or other award granted under the Plan and grant a new
option or award to the award  holder at a lower  exercise  price or otherwise on
more favorable  terms and  conditions  than the canceled  award.  The Plan shall
continue in effect for an unlimited  period,  but may be terminated by the Board
of Directors in its  discretion  at any time.  No ISOs may be granted  under the
Plan after August 31, 2009.

CERTAIN FEDERAL INCOME TAX CONSEQUENCES

      The following is a summary of certain federal income tax aspects of awards
made  under the Plan,  based  upon the laws in  effect on the date  hereof.  All
references to the "Code" are  references  to provisions of the Internal  Revenue
Code of 1986, now in effect.

      Non-Qualified Stock Options.  With respect to non-qualified stock options:
(a) no  income  is  recognized  by the  participant  at the time the  option  is
granted;  (b) upon exercise of the option, the participant  recognizes  ordinary
income in an amount  equal to the  difference  between the option  price and the
fair market value of the shares on the date of exercise; and (c) at disposition,
any  appreciation  after the date of exercise is treated  either as long-term or
short-term capital gain, depending on whether the shares were held for more than
one year by the participant.

      Incentive Stock Options. Generally, no taxable income is recognized by the
participant  upon the grant of an ISO or upon the  exercise of an ISO during the
period of his or her employment  with the Company or one of its  subsidiaries or
within three months (12 months,  in the event of permanent and total disability,
as defined in the Code) after termination.  However,  the exercise of an ISO may
result in an  alternative  minimum  tax  liability  to the  participant.  If the
participant continues to hold the shares acquired upon exercise of an ISO for at
least two years  from the date of grant and one year from the date of  exercise,
upon the sale of the shares,  any amount  realized in excess of the option price
will be taxed as long-term capital gain.

      If Common Stock  acquired upon the exercise of an ISO is disposed of prior
to the expiration of the one-year and two-year holding periods  described above,
the participant will generally  recognize  ordinary income in an amount equal to
the  excess,  if any,  of the fair  market  value of the  shares  on the date of
exercise (or, if less,  the amount  realized on the  disposition  of the shares)
over the option price.  Any further gain  recognized by the  participant on such
disposition will be taxed as short-term or long-term capital gain,  depending on
whether the shares were held for more than one year.

      Stock  Appreciation  Rights. No income will be recognized by a participant
in  connection  with  the  grant  of a  SAR.  When  the  SAR is  exercised,  the
participant will generally  recognize as ordinary income in the year of exercise
an amount equal to the amount of cash received plus the fair market value on the
date of exercise of any shares  received.  If the  participant  receives  Common
Stock upon  exercise  of a SAR,  rules  similar to those  described  above under
"Non-Qualified  Stock  Options"  will  apply with  respect to the  post-exercise
appreciation.

      Restricted Stock A participant  receiving  restricted stock generally will
recognize  ordinary  income  in the  amount  of the  fair  market  value  of the
restricted  stock at the time the restrictions  lapse and the stock vests,  less
the  consideration  paid for the restricted  stock.  However,  a participant may
elect, under Section 83(b) of the Code, to recognize ordinary income on the date
of grant in an amount equal to the excess of the fair market value of the shares
on such date (determined without regard to the restrictions) over their purchase
price. The holding period to determine  whether the participant has long-term or
short-term  capital gain on a  subsequent  disposition  of the shares  generally
begins when the restriction  period  expires,  and the tax basis for such shares
will generally be the fair market value of such shares on such date. However, if
the  participant  has made an election under Section  83(b),  the holding period
will  commence  on the day after the date of  grant,  and the tax basis  will be
equal to the fair  market  value of the shares on the date of grant  (determined
without regard to the restrictions).

      Deferred  Stock A participant  receiving  deferred  stock  generally  will
recognize  ordinary income equal to the amount of cash received in settlement of
the award or the fair market value of the  deferred  stock on the date that such
stock is distributed to the participant, and the capital gain holding period for
such stock will also commence on that date.

      Dividends and Dividend  Equivalents.  Dividends  paid on restricted  stock
prior to the date on which the forfeiture  restrictions  lapse generally will be
treated as compensation  that is taxable as ordinary income to the  participant.
If, however,  the participant makes a Section 83(b) election with respect to the
restricted  stock, the dividends will be taxable as ordinary  dividend income to
the participant.  If dividend  equivalents are credited with respect to deferred
stock or other awards, the participant  generally will recognize ordinary income
when the dividend equivalents are paid.

      Bonus Stock and Director Stock Grants. A participant receiving bonus stock
or a stock grant  generally will recognize  ordinary income on the date of grant
equal to the fair market value of such stock on such date.

      Tax-Offset  Payments.  A participant  receiving a tax-offset  payment will
recognize ordinary income on the date of payment.

      Company  Deductions.  As a general rule, the Company will be entitled to a
deduction  for  federal  income  tax  purposes  at the same time and in the same
amount that an  employee or Outside  Director  recognizes  ordinary  income from
awards  under the Plan,  to the  extent  such  income is  considered  reasonable
compensation  under the Code.  The Company will not,  however,  be entitled to a
deduction  to the  extent  compensation  in excess of $1  million  is paid to an
executive  officer named in a proxy statement of the Company who was employed by
the   Company   at   year-end,    unless   the    compensation    qualifies   as
"performance-based" under Section 162(m) of the Code or certain other exceptions
apply. In addition, the Company will not be entitled to a deduction with respect
to payments to employees  which are contingent  upon a change of control if such
payments are deemed to constitute "excess parachute payments" under Section 280G
of the Code and do not  qualify  as  reasonable  compensation  pursuant  to that
Section; such payments will subject the recipients to a 20% excise tax.

BENEFITS UNDER THE PLAN

      Since the Company  does not have any future  commitments  to grant  awards
under the 1999 Stock  Incentive  Plan, the future awards under this Plan are not
determinable. Therefore, a "New Plan Benefits Table" has not been provided.

ADDITIONAL INFORMATION

      The last sale price of Common Stock on the NASDAQ  National  Market System
on September 8, 1999 as $10 per share.

      THE COMPANY'S BOARD OF DIRECTORS  RECOMMENDS THAT  SHAREHOLDERS VOTE "FOR"
APPROVAL OF THE 1999 STOCK  INCENTIVE  PLAN.  Approval of the Plan requires that
the votes cast in favor of approval  of the Plan  exceed the votes cast  against
such  approval.  Pursuant  to  the  Company's  Bylaws,  abstentions  and  broker
"non-votes"  (shares not voted because a nominee holding shares for a beneficial
owner neither  receives voting  instructions  from the beneficial  owner nor has
discretionary  voting  power with  respect  thereto)  will have no effect on the
vote.



           RATIFICATION OF INDEPENDENT PUBLIC ACCOUNTANTS' APPOINTMENT

      Arthur  Andersen,  LLP has been the independent  auditors of the Company's
accounts  since 1983.  Such firm has no  financial  interest,  either  direct or
indirect, in the Company.  Selection of Arthur Andersen, LLP as the auditors for
the calendar  year ending  December 31, 1999 was made by the Board of Directors,
subject to shareholder ratification. A representative of Arthur Andersen, LLP is
expected  to attend the  meeting  and have an  opportunity  to make a  statement
and/or respond to appropriate questions from shareholders.

      THE COMPANY'S BOARD OF DIRECTORS  RECOMMENDS THAT  SHAREHOLDERS VOTE "FOR"
RATIFICATION  OF THE  APPOINTMENT  OF  ARTHUR  ANDERSEN,  LLP  AS THE  COMPANY'S
INDEPENDENT  PUBLIC  ACCOUNTANTS FOR 1999.  Approval of the  ratification of the
independent public  accountants'  appointment  requires that the number of votes
cast  in  favor  of  approval  of the  ratification  of the  independent  public
accountants'  appointment exceed the number of votes cast against such approval.
Abstentions will have no effect on the vote.

                              SHAREHOLDER PROPOSALS

      The eligibility of shareholders to submit  proposals,  the proper subjects
of shareholder  proposals and other issues governing  shareholder  proposals are
regulated by the rules (the "Shareholder  Proposal Rules") adopted under Section
14 of the  Securities  Exchange Act of 1934,  as amended (the  "Exchange  Act").
Shareholder  proposals  submitted  pursuant to Rule 14a-8 under the Exchange Act
for inclusion in the Company's  proxy  materials for the 2000 Annual  Meeting of
Shareholders must be received by the Company at its principal  executive office,
200 Watson Boulevard, Stratford, Connecticut 06615, no later than Thursday, June
1, 2000.

      In addition,  in  accordance  with recent  amendments  to the  Shareholder
Proposal Rules, written notice of shareholder  proposals to be submitted outside
of Rule 14a-8  described above for  consideration  at the 2000 Annual Meeting of
Shareholders  but not to be included in the Company's  proxy  materials  must be
received by the Company, at the address set forth in the preceding paragraph, on
or before  Wednesday,  August  16,  2000 in order to be  considered  timely  for
purposes of the Shareholder Proposal Rules. The persons designated as proxies by
the Company in connection  with 2000 Annual  Meeting of  Shareholders  will have
discretionary voting authority with respect to any shareholder proposal of which
the Company did not receive timely notice.

                              COSTS OF SOLICITATION

      The costs of soliciting proxies will be borne by the Company.  The Company
will  also  reimburse  brokerage  firms  and  other  custodians,   nominees  and
fiduciaries,  if any, for reasonable  out-of-pocket expenses incurred by them in
connection with forwarding solicitation materials to beneficial owners of Common
Stock  held of record  by such  persons.  Solicitation  by the  Company  will be
primarily by mail.


                   AVAILABILITY OF ANNUAL REPORT ON FORM 10-K

      A copy of the  Company's  Form 10-K for the year ended  December 31, 1998,
including all statements and schedules (but without exhibits), as filed with the
Securities and Exchange Commission, is included herewith.

                            ------------------------

      The  information  under  the  headings  "Compensation  Committee  Report,"
"Compensation  Program  Components,"  "Discussion of 1998  Compensation  for the
Chief Executive Officer" and "Performance Graph" above shall not be deemed to be
"soliciting  material"  or  to be  "filed"  with  the  Securities  and  Exchange
Commission or subject to Regulation  14A or 14C,  other than as provided in Item
402 of Regulation  S-K, or to the  liabilities  of Section 18 of the  Securities
Exchange Act of 1934, as amended, and, unless specific reference is made therein
to such headings,  shall not be  incorporated by reference into any filing under
the Securities Act of 1933, as amended,  or the Securities Exchange Act of 1934,
as amended.




                              DIANON SYSTEMS, INC.
          THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS.

THE UNDERSIGNED HEREBY APPOINTS D.R. SCHREIBER AND C.J. RAUSCH, AND EACH OF
THEM, AS PROXIES, EACH WITH THE POWER TO APPOINT THEIR SUBSTITUTE, AND HEREBY
AUTHORIZES THEM TO REPRESENT AND TO VOTE AS DESIGNATED BELOW ALL THE SHARES OF
COMMON STOCK OF DIANON SYSTEMS, INC. (THE "COMPANY") HELD OF RECORD BY THE
UNDERSIGNED ON SEPTEMBER 8, 1999 AT THE ANNUAL MEETING OF STOCKHOLDERS TO BE
HELD AT THE COMPANY'S CORPORATE HEADQUARTERS AT 200 WATSON BOULEVARD, STRATFORD,
CONNECTICUT, ON OCTOBER 21, 1999 AT 10:00 A.M., AND ANY ADJOURNMENT THEREOF.

PROPOSAL(S): MARK AN X IN THE APPROPRIATE BOX. PLEASE USE EITHER BLUE OR BLACK
INK.

MANAGEMENT/BOARD OF DIRECTORS OF THE REGISTRANT RECOMMENDS A VOTE FOR ALL THE
NOMINEES LISTED IN PROPOSAL 1 AND FOR PROPOSALS 2, 3 AND 4.

1.   ELECTION OF THE FOLLOWING NOMINEES FOR DIRECTOR: KEVIN C. JOHNSON, JOHN P.
     DAVIS, BRUCE K. CROWTHER, E. TIMOTHY GEARY, G. S. BECKWITH GILBERT, JEFFREY
     L. SKLAR AND DAVID R. SCHREIBER.

         [ ] FOR ALL NOMINEES LISTED ABOVE             [ ] WITHHOLD AUTHORITY
                                                           to vote for all
                                                           nominees listed above
TO WITHHOLD YOUR VOTE FOR ANY INDIVIDUAL NOMINEE, WRITE THE NAME(S) ON THE LINE
BELOW.
________________________________________________________________________________
2.   PROPOSAL TO APPROVE THE ADOPTION OF THE EMPLOYEE STOCK PURCHASE PLAN

         [ ] FOR                  [ ] AGAINST          [ ] ABSTAIN
________________________________________________________________________________
3.   PROPOSAL TO APPROVE THE ADOPTION OF THE 1999 STOCK INCENTIVE PLAN

         [ ] FOR                  [ ] AGAINST          [ ] ABSTAIN
________________________________________________________________________________
4.   PROPOSAL TO RATIFY THE APPOINTMENT OF ARTHUR ANDERSEN, LLP AS AUDITORS FOR
     THE YEAR ENDING DECEMBER 31, 1999.

         [ ] FOR                  [ ] AGAINST          [ ] ABSTAIN
________________________________________________________________________________
         [ ] CHECK IF YOU HAVE    [ ] CHECK IF YOU     [ ] CHECK IF YOU PLAN
             MADE ADDITIONAL          PLAN TO ATTEND       TO ATTEND THE MEETING
             COMMENTS                 THE MEETING          AND VOTE YOUR SHARES

                                    (Continued and to be SIGNED on Reverse Side)



THIS PROXY, WHEN PROPERLY EXECUTED, WILL BE VOTED AS DIRECTED OR IF NO CONTRARY
DIRECTION IS INDICATED WILL BE VOTED AS MANAGEMENT RECOMMENDS ON THESE AND ANY
OTHER MATTERS THAT MAY PROPERLY COME BEFORE THE MEETING OR ANY ADJOURNMENT(S) OR
POSTPONEMENT(S) THEREOF. PLEASE SIGN THIS PROXY AND RETURN IT PROMPTLY IN THE
ENVELOPE PROVIDED.

                          Signature of stockholder should correspond exactly
                          with the name shown on the proxy.

                          Corporate officers, powers of attorney, trustees,
                          executors, administrators, guardians, and others
                          signing in a representative capacity should each sign.

                          DATE    ______________________________________________

                                  ______________________________________________
                                           (SIGNATURE OF SHAREHOLDER)
                                  ______________________________________________
                                           (SIGNATURE IF HELD JOINTLY)

                                  If time warrants, improperly signed cards will
                                           be returned for correction.