Registration No. ___________

   As filed with the Securities and Exchange Commission on December __, 1996
 ------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                              --------------------

                                    FORM S-8

                             Registration Statement

                                      Under

                           The Securities Act of 1933

                              DIANON SYSTEMS, INC.
                              --------------------
             (Exact name of registrant as specified in its charter)

               Delaware                                  06-1128081
               --------                                  ----------
       (State or other jurisdiction of                  (IRS Employer
       incorporation or organization)                Identification No.)

  200 Watson Boulevard, Stratford, Connecticut              06497
  --------------------------------------------              -----
  (Address of Principal Executive Offices)                (Zip Code)


              Dianon Systems, Inc. 1996 Stock Incentive Plan and
                 Stock Options Granted Not Pursuant to a Plan
                ----------------------------------------------
                          (Full title of the plans)


                               Richard A. Sandberg
    Dianon Systems, Inc., 200 Watson Boulevard, Stratford, Connecticut 06497
                                 (203) 381-4000
    ------------------------------------------------------------------------
            (Name, address and telephone number of agent for service)

                       Copy to: Gloria W. Nusbacher, Esq.
                            Hughes Hubbard & Reed LLP
                             One Battery Park Plaza
                              New York, N.Y. 10004




                                           CALCULATION OF REGISTRATION FEE

        Title of
       Securities                 Amount              Proposed Maximum               Proposed               Amount of
          to be                    to be               Offering Price           Maximum Aggregate          Registration
       Registered              Registered**             Per Share***            Offering Price***              Fee
- -------------------------- ---------------------- -------------------------- ------------------------- ---------------------

                                                                                                       
      Common Stock,               710,000                $7.81                  $5,543,411.57               $1680
        par value                 shares
     $.01 per share*
- -------------------------- ---------------------- -------------------------- ------------------------- ---------------------
                                                                                        (see footnotes on following page)

                                                Page 1 of 13 Pages.





FOOTNOTES
- ---------

  *      Each share of Common  Stock  includes a related  right (a  "Right")  to
         purchase  junior  participating  preferred  stock of the  Company.  The
         Rights are not exercisable or transferable  apart from the Common Stock
         at this time, and  accordingly no independent  value is attributable to
         such Rights.

  **     This Registration  Statement also relates to such indeterminate  number
         of additional  shares (and related Rights) as may be issuable  pursuant
         to stock splits, stock dividends,  or similar  transactions,  and to an
         indeterminate amount of deferred compensation obligations to be offered
         and  sold  pursuant  to the  employee  benefit  plan  covered  by  this
         Registration Statement.

 ***     The proposed  maximum  offering price per share of Common Stock and the
         proposed maximum aggregate offering price are calculated solely for the
         purpose of  determining  the  registration  fee pursuant to Rule 457(h)
         under the  Securities  Act of 1933.  With respect to 236,353  shares of
         Common  Stock as to which stock  options  were  granted  under the Plan
         prior  to  December  20,  1996,  the  registration  fee is based on the
         weighted average exercise price per share of $6.30; and with respect to
         the balance of the shares being registered, the fee is based on a price
         of  $8.56  per  share,  which is the  average  of the high and low sale
         prices of the  Common  Stock on  December  20,  1996,  as quoted on the
         NASDAQ National Market.






                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT




Item 3.  Incorporation of Documents by Reference
         ---------------------------------------

         The following  documents filed by Dianon Systems,  Inc. (the "Company")
under the Securities  Exchange Act of 1934 (the "Exchange Act") are incorporated
herein by reference:

         (a) The  Company's  Annual  Report  on Form  10-K  for the  year  ended
     December 31, 1995;

         (b) All other reports filed by the Company pursuant to Section 13(a) or
     15(d) of the Exchange Act since December 31, 1995; and

         (c) The description of the Company's  Common Stock and Rights contained
     in the Company's registration statements therefor and subsequent amendments
     thereof.

         All documents filed by the Company  pursuant to Sections 13(a),  13(c),
14 and 15(d) of the Exchange Act after the date of this  Registration  Statement
and prior to the filing of a  post-effective  amendment which indicates that all
securities  offered  hereby have been sold or which  deregisters  all securities
then remaining  unsold,  shall be deemed to be incorporated by reference in this
Registration  Statement  and to be a part  hereof from the date of the filing of
such documents.


Item 4.  Description of Securities
         -------------------------

         Not applicable.


Item 5.  Interests of Named Experts and Counsel
         --------------------------------------

         Not applicable.


Item 6.  Indemnification of Directors and Officers
         -----------------------------------------

         Under  Section  145 of the  General  Corporation  Law of the  State  of
Delaware (the "DGCL"),  any director or officer as well as any other employee or
individual may be indemnified  against  expenses  (including  attorneys'  fees),
judgments, fines and amounts paid in settlement actually and reasonably incurred
by such person in  connection  with  certain  threatened,  pending or  completed
actions,  suits or  proceedings,  whether  civil,  criminal,  administrative  or
investigative  (other  than an  action by or in the  right of the  Company  -- a
"derivative  action") to which such person is or was a party or is threatened to
be made a party by reason of the fact  that  such  person is or was a  director,





officer, employee, or agent of the Company or is or was serving at the Company's
request in such  capacity for another  entity if such person acted in good faith
and in a manner such person  reasonably  believed to be in or not opposed to the
best  interests of the  Company,  and,  with  respect to any criminal  action or
proceeding,  had no  reasonable  cause to  believe  such  person's  conduct  was
unlawful.  A similar  standard of care is  applicable  in the case of derivative
actions  to which  such a person is or was a party by  reason  of such  person's
status or capacity as described above, except that  indemnification only extends
to expenses (including attorneys' fees) actually and reasonably incurred by such
person in  connection  with the defense or  settlement of such an action and the
DGCL  requires  approval by the court in which such  action was  brought  before
there can be any  indemnification  where the person seeking  indemnification has
been found  liable to the  Company.  Additionally,  the  Company is  required to
indemnify its  directors and officers  against  expenses  (including  attorneys'
fees)  actually and  reasonably  incurred by such person to the extent that such
directors or officers have been successful on the merits or otherwise in defense
of any such  action,  suit or  proceeding  or in defense of any claim,  issue or
matter referred to in Section 145 of the DGCL.

         Unless ordered by a court,  indemnification  can be made by the Company
only upon a  determination,  by one of several means,  that  indemnification  is
proper in the circumstances  because the party seeking  indemnification  has met
the applicable  standard of conduct as set forth in Section 145 of the DGCL. The
indemnification  provided  by Section 145 of the DGCL  includes  the right of an
officer or director to be paid by the Company the expenses incurred in defending
any such proceedings in advance of their final disposition. Such advance payment
of  expenses,  however,  may be made only upon  delivery  to the  Company by the
indemnified party of an undertaking to repay all amounts so advanced if it shall
ultimately be determined that the person receiving such payments is not entitled
to be indemnified pursuant to Section 145 of the DGCL.

         The rights to indemnification  and advancement of expenses conferred by
Section  145 of the DGCL shall not be deemed  exclusive  of any other  rights to
which the person seeking  indemnification  or advancement  may be entitled under
any bylaw,  agreement,  vote of  stockholders  or  disinterested  directors,  or
otherwise.  In  addition,  Section  145 of the DGCL  authorizes  the  Company to
purchase and maintain insurance,  at its expense, on behalf of any person who is
or was a  director,  officer,  employee  or  agent of the  Company  or is or was
serving at the Company's request in such capacity for another entity against any
liability asserted against,  or incurred by, such person in any such capacity or
arising out of such status,  whether or not the Company  would have the power to
indemnify such person against such liability under Section 145 of the DGCL.

         Article TENTH of the Company's  Restated  Certificate of  Incorporation
("Article  10")  provides  that no director  shall be  personally  liable to the
Company or its  stockholders  for  monetary  damages for any breach of fiduciary
duty in such capacity, except for liability (i) for any breach of the director's
duty of loyalty to the Company or its  stockholders,  (ii) for acts or omissions
not in good faith or which involve intentional misconduct or a knowing violation
of law,  (iii) under Section 174 of the DGCL, or (iv) for any  transaction  from
which the  director  derived an improper  personal  benefit.  Article 10 further





provides that if the DGCL is amended after the date of the Restated  Certificate
of Incorporation to authorize  corporate action further  eliminating or limiting
the personal  liability  of  directors,  then the  liability of directors of the
Company shall be eliminated  or limited to the fullest  extent  permitted by the
DGCL, as so amended.

         Article 10 further  provides  that the Company  shall  indemnify to the
fullest  extent  permitted  by the laws of the State of Delaware as from time to
time in effect any person  who was or is a party or is  threatened  to be made a
party to, or otherwise  requires  representation  by counsel in connection with,
any threatened,  pending or completed action, suit or proceeding, whether civil,
criminal, administrative or investigative (whether or not an action by or in the
right of the  Company),  by reason of the fact that he is or was a  director  or
officer  of the  Company  or,  while  serving  as a  director  or officer of the
Company, is or was serving at the request of the Company as a director, officer,
employee or agent of another corporation,  partnership,  joint venture, trust or
other  enterprise,  or by reason of any  action  alleged  to have been  taken or
omitted in such capacity. Article 10 further provides that such persons have the
right to be paid in advance by the Company for their expenses to the full extent
permitted by the laws of the State of Delaware as from time to time in effect.

         The rights and  authority  conferred in Article 10 are not exclusive of
any other  right  which  any  person  may have or  acquire  under  any  statute,
provision of the Restated  Certificate of  Incorporation or the Restated By-Laws
of the Company,  agreement,  vote of stockholders or disinterested  directors or
otherwise.  Article 10 further  provides that neither the amendment or repeal of
Article 10 nor the  adoption of any  provision of the  Restated  Certificate  of
Incorporation  or Restated By-Laws or of any statute  inconsistent  with Article
10, shall eliminate or reduce the effect of Article 10 in respect of any acts or
omissions  occurring  prior  to  such  amendment,   repeal  or  adoption  of  an
inconsistent provision.

         Officers  and  directors  of  the  Company  are  presently  covered  by
insurance which (with certain  exceptions and certain  limitations)  indemnifies
them against  losses or  liabilities  arising from any alleged  "wrongful  act",
including breach of duty, neglect,  error,  misstatement,  misleading statement,
omission or other acts done or wrongfully attempted.


Item 7.  Exemption from Registration Claimed
         -----------------------------------

         Not applicable.


Item 8.  Exhibits
         -------




Number          Description                                        Method of Filing
- ------          -----------                                        ----------------

                                                             
4.1             Restated Certificate of Incorporation of the       Filed as Exhibit 3.1 to the Company's
                Company, as amended through June 12, 1991          Registration Statement No. 33-41226









Number          Description                                        Method of Filing
- ------          -----------                                        ----------------

                                                             
4.2             Restated By-Laws of the Company, as amended        Filed herewith
                through October 24, 1996

4.3             Rights Agreement, dated as of April 29, 1994,      Filed as Exhibit 1 to the Company's Form 8-K
                between the Company and American Stock Transfer    dated April 29, 1994, filed with the Securities
                and Trust Company, as Rights Agent                 and Exchange Commission on May 9, 1994

4.4             Amendment, dated as of October 4, 1995, to the     Filed as Exhibit 2 to the Company's Form 8-K
                Rights Agreement between the Company and           dated October 4, 1995, filed with the
                American Stock Transfer and Trust Company          Securities and Exchange Commission on
                                                                   November 8, 1995

5.1             Opinion of Hughes Hubbard & Reed LLP               Filed herewith

23.1            Consent of Arthur Andersen LLP                     Filed herewith

24.1            Powers of Attorney authorizing Richard A.          Filed herewith
                Sandberg and Kevin C. Johnson to sign the
                Registration Statement and all amendments
                thereto on behalf of certain directors and
                officers of the Company



Item 9.  Undertakings
         ------------

(a)    The Company hereby undertakes:

            (1) To file,  during any  period in which  offers or sales are being
       made, a post-effective amendment to this Registration Statement:

                (i)   To include any  prospectus required by Section 10(a)(3) of
             the Securities Act of 1933;

                (ii)  To reflect in the  prospectus  any facts or events arising
             after the effective date of the Registration Statement (or the most
             recent post-effective amendment thereof) which,  individually or in
             the aggregate,  represents a fundamental  change in the information
             set forth in the Registration Statement;

                (iii) To include any  material  information  with respect to the
             plan of distribution  not previously  disclosed in the Registration
             Statement  or  any  material  change  to  such  information  in the
             Registration Statement.




       Provided,  however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
       if the information required to be included in a post-effective  amendment
       by those paragraphs is contained in periodic reports filed by the Company
       pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of
       1934 that are incorporated by reference in the Registration Statement.

            (2)  That, for the purpose of  determining  any liability  under the
       Securities  Act of 1933,  each  such  post-effective  amendment  shall be
       deemed to be a new  registration  statement  relating  to the  securities
       offered  therein,  and the offering of such securities at that time shall
       be deemed to be the initial bona fide offering thereof.

            (3)  To  remove  from  registration  by  means  of a  post-effective
       amendment any of the securities  being  registered which remain unsold at
       the termination of the offering.

(b)    The Company hereby undertakes  that,  for  purposes  of  determining  any
liability under the Securities Act of 1933, each filing of the Company's  annual
report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act
of 1934 (and, where applicable, each filing of an employee benefit plan's annual
report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is
incorporated by reference in the Registration  Statement shall be deemed to be a
new registration  statement relating to the securities offered therein,  and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof.

(c)    Insofar as indemnification  for liabilities arising under the  Securities
Act of 1933 may be permitted to directors,  officers and controlling  persons of
the Company pursuant to the foregoing provisions,  or otherwise, the Company has
been advised that in the opinion of the Securities and Exchange  Commission such
indemnification  is  against  public  policy  as  expressed  in the  Act and is,
therefore,  unenforceable. In the event that a claim for indemnification against
such liabilities  (other than the payment by the Company of expenses incurred or
paid  by a  director,  officer  or  controlling  person  of the  Company  in the
successful  defense of any  action,  suit or  proceeding)  is  asserted  by such
director,  officer or controlling person in connection with the securities being
registered,  the Company  will,  unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.






                                   SIGNATURES


         The Registrant.  Pursuant to the  requirements of the Securities Act of
1933, the Registrant certifies that it has reasonable grounds to believe that it
meets all of the  requirements  for filing on Form S-8 and has duly  caused this
Registration Statement to be signed on its behalf by the undersigned,  thereunto
duly authorized, in the City of Stratford, State of Connecticut, on this 5th day
of December, 1996.

                                   DIANON SYSTEMS, INC.



                                   By:  RICHARD A. SANDBERG*
                                        -------------------
                                        Richard A. Sandberg
                                        Chairman of the Board



         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement  has been signed below by the  following  persons in the
capacities indicated on this 5th day of December, 1996.



Signature                               Capacity
- ---------                               --------



RICHARD A. SANDBERG *                   Chairman of  the  Board (principal
- -------------------------               financial officer)
       Richard A. Sandberg



KEVIN C. JOHNSON *                      Director and President (principal 
- -------------------------               executive officer)
       Kevin C. Johnson



JAMES B. AMBERSON *                     Director, Chief Medical Officer and
- -------------------------               Senior Vice President, Operations
       James B. Amberson, M.D.



JOHN P. DAVIS *                         Director
- -------------------------
       John P. Davis









Signature                               Capacity
- ---------                               --------



WALTER O. FREDERICKS *                  Director
- -------------------------
       Walter O. Fredericks



G.S. BECKWITH GILBERT *                 Director
- -------------------------
       G.S. Beckwith Gilbert



JEFFREY L. SKLAR *                      Director
- -------------------------
       Jeffrey L. Sklar, M.D., Ph.D.



DAVID R. SCHREIBER *                    Principal accounting officer
- -------------------------
       David R. Schreiber


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

*      By:
          -----------------------------------------
          Richard A. Sandberg, for himself and, as
          authorized by Power of Attorney filed as
          Exhibit 24.1 to this Registration Statement







                                  EXHIBIT INDEX
                                  -------------




Number          Description                                        Method of Filing
- ------          -----------                                        ----------------

                                                             
4.1             Restated Certificate of Incorporation of the       Filed as Exhibit 3.1 to the Company's
                Company, as amended through June 12, 1991          Registration Statement No. 33-41226

4.2             Restated By-Laws of the Company, as amended        Filed herewith
                through October 24, 1996

4.3             Rights Agreement, dated as of April 29, 1994,      Filed as Exhibit 1 to the Company's Form 8-K
                between the Company and American Stock Transfer    dated April 29, 1994, filed with the Securities
                and Trust Company, as Rights Agent                 and Exchange Commission on May 9, 1994

4.4             Amendment, dated as of October 4, 1995, to         Filed as Exhibit 2 to the Company's Form 8-K
                Rights Agreement between the Company and           dated October 4, 1995, filed with the
                American Stock Transfer and Trust Company          Securities and Exchange Commission on
                                                                   November 8, 1995

5.1             Opinion of Hughes Hubbard & Reed LLP               Filed herewith

23.1            Consent of Arthur Andersen LLP                     Filed herewith

24.1            Powers of Attorney authorizing Richard A.          Filed herewith
                Sandberg and Kevin C. Johnson to sign the
                Registration Statement and all amendments
                thereto on behalf of certain directors and
                officers of the Company