SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                   Form 10-Q/A


              (X) QUARTERLY REPORT PURSUANT TO SECTION 13 or 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                For the Quarterly Period Ended December 31, 1999

                                       OR

              ( )TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                        For the transition period from to
                         Commission file number 0-14902


                           MERIDIAN DIAGNOSTICS, INC.
- --------------------------------------------------------------------------------
Incorporated under the laws of Ohio                           31-0888197
- --------------------------------------------------------------------------------
                                            (I.R.S. Employer Identification No.)

                             3471 River Hills Drive
                             Cincinnati, Ohio 45244
                                 (513) 271-3700

Indicate  by a check  mark  whether  the  Registrant  (1) has filed all  reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
Registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days.

                                  Yes |X| No __


Indicate the number of shares  outstanding  of each of the  issuer's  classes of
common stock, as of the latest practicable date.


           Class                                   Outstanding February 13, 1999
 --------------------------                        -----------------------------
 Common Stock, no par value                                  14,585,588





                                       1





The  Company's  December 31, 1999 and September  30, 1999  consolidated  balance
sheets and the  consolidated  statement  of  shareholders'  equity for the three
months ended December 31, 1999 have been restated to reflect the correction of a
book-keeping error which occurred in June 1999 related to sales to the Company's
German  subsidiary.  This restatement amends the following sections of this Form
10-Q:

     Part I,  Item 1 - Financial Statements;

     Part II, Item 6 - Exhibits and Reports on Form 8-K
                       (Exhibit 27 - Financial Data Schedule)






                                       2





                   MERIDIAN DIAGNOSTICS, INC. AND SUBSIDIARIES

                    INDEX TO QUARTERLY REPORT ON FORM 10-Q/A



                                                                         Page(s)
                                                                         -------
PART I    FINANCIAL INFORMATION

Item 1.   Financial Statements
                Consolidated Balance Sheets
                December 31, 1999 (Restated) and
                September 30, 1999 (Restated)                             3-4

                Consolidated Statements of Earnings
                Three Months Ended December 31, 1999 and 1998              5

                Consolidated Statement of Shareholders' Equity
                Three Months Ended December 31, 1999 (Restated)            6

                Consolidated Statements of Cash Flows
                Three Months Ended December 31, 1999 and 1998              7

                Notes to Consolidated Financial Statements              8-12

Item 2.   Management's Discussion and Analysis of
          Financial Condition and Results of Operations                12-14

PART II.  OTHER INFORMATION

Item 5.   Other Information                                               15
Item 6.   Exhibits and Reports on Form 8-K
                Signature                                                 16
                Exhibit 27 Financial Data Schedule (Restated)          17-19
                Exhibit 99 Forward Looking Statements                     20






                                       3




                   MERIDIAN DIAGNOSTICS, INC. AND SUBSIDIARIES
                 Consolidated Balance Sheets (Restated - Note 1)
                                   (Unaudited)
                                     ($000)

                                     ASSETS



                                                 December 31,     September 30,
                                                1999 (Restated)  1999 (Restated)
                                               ----------------  ---------------
CURRENT ASSETS:
  Cash and cash equivalents                        $    9,031      $   6,229
  Investments                                           1,003          1,002
  Accounts receivable and notes receivable,
     less allowance of $400 in 2000 and
     $380 in 1999 for doubtful accounts                12,426         12,508
  Inventories                                          10,688         10,357
  Prepaid expenses and other                              999          1,086
  Deferred tax assets                                     562            562
                                                   ----------      ----------

     Total current assets                              34,709         31,744
                                                   ----------      ----------

PROPERTY, PLANT AND EQUIPMENT:
  Land                                                    969            969
  Buildings and improvements                            7,277         10,427
  Machinery, equipment and furniture                   12,276         11,986
  Construction in progress                              2,108            811
  Assets held for sale                                  3,150             --
                                                   ----------      ----------
  Total property, plant and equipment                  25,780         24,193
  Less-accumulated depreciation and amortization       10,687          9,987
                                                   ----------      ----------

     Net property, plant and equipment                 15,093         14,206
                                                   ----------      ----------

OTHER ASSETS:
  Long term receivables and other                         790            940
  Deferred debenture offering costs,
     net of accumulated amortization of
     $441 in 2000 and $407 in 1999                        888            922
  Other intangible assets, net of
     accumulated amortization of $9,917 in
     2000 and $9,258 in 1999                           20,101         20,760
  Cost in excess of net assets acquired,
     net of accumulated amortization of
     $862 in 2000 and $806 in 1999                      3,533          3,589
                                                    ---------       ---------

     Total other assets                                25,312         26,211
                                                    ---------       ---------

TOTAL ASSETS                                        $  75,114       $ 72,161
                                                    =========       =========



The accompanying notes to consolidated financial statements are an integral part
of these unaudited balance sheets.



                                       4





                   MERIDIAN DIAGNOSTICS, INC. AND SUBSIDIARIES
                 Consolidated Balance Sheets (Restated - Note 1)
                                   (Unaudited)
                                     ($000)


                      LIABILITIES AND SHAREHOLDERS' EQUITY



                                                December 31,     September 30,
                                              1999 (Restated)    1999 (Restated)
                                              ---------------    ---------------
CURRENT LIABILITIES:
      Current portion of long-term and
        capital lease obligations                 $    853           $    821
      Notes payable to bank                          3,354              3,354
      Notes payable to third party                    --                1,000
      Accounts  payable                              3,213              3,495
      Accrued payroll and payroll taxes              1,930              2,154
      Accrued expenses                               2,680              2,778
      Income taxes payable                             600               --
                                                  --------           --------

         Total current liabilities                  12,630             13,602
                                                  --------           --------

LONG-TERM AND CAPITAL LEASE OBLIGATIONS:            25,188             21,366
                                                  --------           --------

DEFERRED TAX LIABILITIES                             3,430              3,602
                                                  --------           --------

SHAREHOLDERS' EQUITY:

      Preferred stock, no par value,
         1,000,000 shares authorized;
         none issued
      Common stock, no par value,
         50,000,000 shares authorized;
         14,585,390 and 14,429,151 shares
         issued and outstanding,
         respectively, stated at                     2,529              2,424
      Additional paid-in capital                    20,920             20,855
      Retained earnings                             11,872             11,131
      Accumulated other comprehensive loss          (1,455)              (819)
                                                  --------           --------

         Total  shareholders' equity                33,866             33,591
                                                  --------           --------

TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY        $ 75,114           $ 72,161
                                                  ========           ========


The accompanying notes to consolidated financial statements are an integral part
of these unaudited balance sheets.



                                       5








                   MERIDIAN DIAGNOSTICS, INC. AND SUBSIDIARIES
                       Consolidated Statements of Earnings
                                   (Unaudited)
                        ($000, except earnings per share)


                                                       Three Months Ended
                                                          December 31,
                                                  --------------------------
                                                     1999          1998
                                                  -----------    -----------
NET SALES                                          $  14,329     $   11,720

COST OF SALES                                          5,207          4,088
                                                  -----------    -----------

      Gross profit                                     9,122          7,632
                                                  -----------    -----------

OPERATING EXPENSES:
      Research and development                           522            537
      Selling and marketing                            3,127          2,851
      General and administrative                       2,772          2,318
      Merger integration                                   -            526
                                                  -----------    -----------

      Total operating expenses                         6,421          6,232
                                                  -----------    -----------

      Operating income                                 2,701          1,400

OTHER INCOME (EXPENSE):
      Interest income                                     69            189
      Interest expense                                 (475)          (602)
      Other, net                                          80             50
                                                  -----------    -----------
      Total other income (expense)                     (326)          (363)

                                                  -----------    -----------
      Earnings before income taxes                     2,375          1,037

INCOME TAXES                                             905            483

                                                  ===========    ===========
NET EARNINGS                                      $    1,470     $      554
                                                  ===========    ===========

BASIC  WEIGHTED AVERAGE NUMBER
  OF COMMON SHARES OUTSTANDING                        14,502         14,382
                                                  ===========    ===========

BASIC EARNINGS PER COMMON SHARE                   $      .10     $      .04
                                                  ===========    ===========

DILUTED WEIGHTED AVERAGE NUMBER
  OF COMMON SHARES OUTSTANDING                        14,580         14,554
                                                  ===========    ===========

DILUTED EARNINGS PER COMMON SHARE                  $     .10     $      .04


The accompanying notes to consolidated financial statements are an integral part
of these unaudited statements.





                                       6





                   MERIDIAN DIAGNOSTICS, INC. AND SUBSIDIARIES
                     Consolidated Statement of Shareholders'
               Equity For the Three Months Ended December 31, 1999
                               (Restated - Note 1)
                                     ($000)






                                        Number of
                                         Shares                                          Accumulated
                                       Issued and                            Additional       Other
                                       Outstanding  Comprehensive    Common   Paid in    Comprehensive    Retained
                                          (000)     Income (Loss)    Stock    Capital        Loss         Earnings      Total
                                       -----------  -------------   -------- ---------   -------------    ---------    --------

                        >                                                                         
Balance at September 30, 1999             14,429           ---       $2,424     $20,855        $(819)      $11,131     $33,591
Exercised Stock Options, Net                 156           ---          105          65           ---          ---         170
Dividends                                    ---           ---          ---         ---           ---        (729)       (729)
Comprehensive Income (loss)
      Net income                             ---         1,470          ---         ---           ---        1,470       1,470
      Other comprehensive income
      (loss)
         Foreign currency
         translation adjustment              ---         (636)          ---         ---         (636)          ---       (636)

Comprehensive Income                         ---           834          ---         ---           ---          ---         ---
                                          -------      ========      -------    --------     --------      -------     -------

Balance at December 31, 1999              14,585                     $2,529     $20,920      $(1,455)      $11,872     $33,866
                                          ======                     ======     =======      =======       =======     =======


The accompanying notes to consolidated financial statements are an integral part
of these unaudited statements.





                                       7




                   MERIDIAN DIAGNOSTICS, INC. AND SUBSIDIARIES
                      Consolidated Statements of Cash Flows
                                   (Unaudited)
                                     ($000)

                                                         Three Months Ended
                                                            December 31,
                                                      --------------------------
                                                        1999            1998
                                                      -------      -----------
CASH FLOWS FROM OPERATING ACTIVITIES:
   Net earnings                                       $ 1,470       $     554
   Non cash items:
      Depreciation of property, plant
        and equipment                                     833             673
      Amortization of intangible assets
        and deferred royalties                            763             399
      Deferred income taxes                              (172)             516
   Change in current assets and current
      liabilities net of effects of
        acquisition:
          Change in current assets excluding
            cash/cash equivalents and
            investments                                  (376)           2,683
          Change in current liabilities,
            excluding current portion of
            long-term obligations                      (1,219)             456
   Long-term receivable and payable                        133             339
                                                      ---------      ----------
      Net cash provided by operating activities          1,432           5,620
                                                      ---------      ----------

CASH FLOWS FROM INVESTING ACTIVITIES:
   Acquisition of Gull Laboratories,
     Inc., net of cash acquired                             --        (17,140)
   Purchase of property, plant and
     equipment, net                                     (1,289)           (437)
   Purchase of short term investments                      (1)           (622)
   Purchase of product  license                             --           (200)
                                                      ---------      ----------
      Net cash (used for) investing activities          (1,290)        (18,399)

CASH FLOWS FROM FINANCING ACTIVITIES:
   Proceeds from other long-term obligations             3,478              --
   Repayment of long-term obligations                    (145)           (840)
   Dividends paid                                        (729)           (720)
   Proceeds from issuance of common stock                  170               2
                                                      ---------      ----------
      Net cash provided by (used for)
        financing activities                             2,774         (1,558)
                                                      ---------
                                                                     ----------

EFFECT OF EXCHANGE RATE CHANGES ON CASH                  (114)             (6)

                                                      ---------
                                                                     ----------
NET INCREASE (DECREASE) IN
CASH AND CASH EQUIVALENTS                                2,802        (14,343)

CASH & CASH EQUIVALENTS AT BEGINNING OF PERIOD           6,229          19,400

                                                      =========      ==========
CASH & CASH EQUIVALENTS AT END OF PERIOD              $  9,031       $   5,057
                                                      =========      ==========

SUPPLEMENTAL DISCLOSURE OF
 CASH FLOW INFORMATION:
   Cash paid during the period for:
      Income taxes                                    $    358       $       4
      Interest                                             113             392
     Non-cash items
        Capital lease                                      522              --

The accompanying notes to consolidated financial statements are an integral part
of these unaudited statements.


                                       8




                   MERIDIAN DIAGNOSTICS, INC. AND SUBSIDIARIES
                   Notes to Consolidated Financial Statements
                                   (Unaudited)


1.   Basis of Presentation:

     The  consolidated  financial  statements  included  herein  have  not  been
     examined by independent  public  accountants,  but include all  adjustments
     (consisting  of normal  recurring  entries)  which are,  in the  opinion of
     management,  necessary  for a fair  presentation  of the  results  for such
     periods.

     Certain  information and footnote disclosure normally included in financial
     statements  prepared  in  accordance  with  generally  accepted  accounting
     principles have been omitted pursuant to the requirements of the Securities
     and Exchange Commission, although the Company believes that the disclosures
     included in these financial statements are adequate to make the information
     not misleading.

     It is suggested  that these  consolidated  financial  statements be read in
     conjunction  with  consolidated  financial  statements  and  notes  thereto
     included in the Company's latest annual report on Form 10-K, as amended.

     The  results of  operations  for the interim  periods  are not  necessarily
     indicative of the results to be expected for the year.

     The December 31, 1999 and September 30, 1999  consolidated  balance  sheets
     and the consolidated statement of shareholders' equity for the three months
     ended December 31, 1999 included herein,  have been restated to reflect the
     correction  of a bookkeeping  error which  occurred in June 1999 related to
     sales to the Company's German subsidiary. The impact of this restatement to
     earnings for the year ended  September 30, 1999 is as follows (in thousands
     except per share amounts):

                                     As Reported     Correction   As Restated
                                    ------------   ------------   -------------
     Net sales                          $54,351     $(424)         $53,927

     Cost of sales                       19,473        85           19,558

                                    ------------   ------------   -----------
        Gross profit                     34,878      (509)          34,369

     Earnings before income taxes         5,321      (509)           4,812

     Provision for income taxes           2,935      (196)           2,739

     Net income                           2,386      (313)           2,073

     Basic earnings per share              0.17     (0.03)            0.14

     Dilutive earnings per share           0.16     (0.02)            0.14


     The  Company  has  filed an  amended  Annual  Report  on Form 10-K with the
     Securities  and  Exchange   Commission   that  includes  fiscal  year  1999
     consolidated  financial  statements  that have been restated for the matter
     described above.




                                       9





2.   Acquisition of Gull Laboratories, Inc.:

     On November 5, 1998, the Company  acquired Gull  Laboratories,  Inc. (Gull)
     for $19,700,000 cash, including  acquisition costs of $1,700,000.  Gull was
     engaged in the  development,  manufacture  and  marketing  of  high-quality
     diagnostic  test  kits  for  the  detection  of  infectious   diseases  and
     autoimmune disorders.  The acquisition was accounted for as a purchase. For
     accounting purposes,  the acquisition was effective on October 31, 1998 and
     the results of operations of Gull are included in the consolidated  results
     of operations of the Company from that date forward.

     The following  unaudited pro forma  combined  results of operations for the
     quarter ended December 31, 1998,  assumes the Gull acquisition  occurred as
     of October 1, 1998 (dollars in thousands, except per share data). Pro forma
     adjustments consist of reductions in interest income due to the use of cash
     and  investments  to  fund  the  acquisition,  additional  amortization  of
     intangible  assets  and  goodwill  and  adjustments  to the  tax  provision
     assuming  the  utilization  of a  portion  of  Gull  U.S.  losses  and  the
     establishment of valuation reserves for potentially  unrealizable  deferred
     tax assets related to pro forma European operating losses.

     The unaudited pro forma financial  information presented is not necessarily
     indicative of either the results of operations that would have occurred had
     the acquisition taken place on October 1, 1998 or the results of operations
     of the combined companies.

                                                      3 Months Ended
                                                     December 31, 1998
                                                     -----------------

     Net sales.............................           $      13,210
     Net earnings..........................           $         627
     Earnings per share:
          Basic............................           $        0.04
          Diluted..........................           $        0.04


     During fiscal 1999,  research and development  activities were consolidated
     into Meridian's  Cincinnati operations and production facilities in Germany
     were  shut  down.  The   renovation  of  the   Cincinnati   facilities  was
     substantially complete as of December 31, 1999, and the manufacture of Gull
     products is now conducted in Cincinnati.  The facility in Salt Lake City is
     currently being marketed for sale.

     Purchase  liabilities  recorded  included   approximately   $1,400,000  for
     severance  and  costs  related  to the shut down and  consolidation  of the
     acquired  facilities  in Salt Lake City and Germany.  Substantially  all of
     this amount has been paid as of December 31, 1999. In  connection  with the
     acquisition,  the Company agreed to pay certain amounts owed by Gull to its
     former parent company. At September 30, 1999,  $1,000,000 was recorded as a
     note payable to third party  representing  the final amount  payable to the
     former parent. This note was paid on November 16, 1999.



                                       10




     The major  components of the merger  integration  costs incurred during the
     first quarter of fiscal 1999 were as follows:

             --------------------------------------------------- --------------
             ($ in thousands)                                       Amount
             --------------------------------------------------- --------------
             Travel and training                                 $         251
             Termination payments to distributors                          275
             --------------------------------------------------- --- ----------
             Total merger integration costs                      $         526
             --------------------------------------------------- --- ----------

     Substantially  all merger  integration  costs were paid as of September 30,
     1999.  First quarter fiscal 2000 merger  integration  costs were immaterial
     and are expected to be immaterial for the remainder of fiscal year 2000.

3.   Inventories:


     Inventories are comprised of the following (amounts in thousands):

                           December 31, 1999      September 30, 1999
                           -----------------      ------------------

      Raw materials           $   2,550                $   2,469
      Work-in-process             3,315                    3,211
      Finished goods              4,823                    4,677
                              ----------               ----------
                              $  10,688                $  10,357
                              ==========               ==========

4.   Income Taxes:

     The provisions  for income taxes were computed at the estimated  annualized
     effective  tax rates  utilizing  current  tax law in effect,  after  giving
     effect to research and  experimentation  credits and  recognizing a benefit
     for first quarter losses incurred in the Gull European operations.

5.   Earnings Per Common Share:

     Basic earnings per share (EPS) is computed by dividing income  available to
     common  shareholders  by the  weighted  average  number  of  common  shares
     outstanding.  Diluted  EPS is computed  by adding to the  weighted  average
     number of common  shares  outstanding,  the dilutive  effect of  additional
     common shares that would have been outstanding if dilutive potential common
     shares had been issued.




                                       11




     The table below shows the amounts used in computing  earnings per share and
     the effect of dilutive  potential  common  stock on income and the weighted
     average  number of shares for the three months ended  December 31, 1999 and
     December 31, 1998.




                                                                       QUARTER ENDED

                                            December 31, 1999                                 December 31, 1998
                               --------------------------------------------      --------------------------------------------
                                 Income           Shares         Per Share         Income            Shares         Per Share
                               (Numerator)     (Denominator)       Amount        (Numerator)     (Denominator)       Amount
                                ---------       -----------      ----------       ---------       -----------       ---------
     In thousands,
     except per share
     amounts
     -----------------------
                                                                                                    
     BASIC
     EARNINGS PER
     SHARE

     Net income
     available
     to common
     shareholders                 $1,470            14,502          $0.10             $554            14,382          $0.04
     ----------------------- ---------------- ----------------- -------------- ---------------- ----------------- --------------

     EFFECT OF DILUTIVE
     SECURITIES

     Stock Options                   ---                78            ---              ---               172            ---
     ----------------------- ---------------- ----------------- -------------- ---------------- ----------------- --------------

     DILUTED EARNINGS PER
     SHARE

     Net income
     available
     to common
     shareholders
     and assumed
     conversions                  $1,470            14,580          $0.10             $554            14,554          $0.04
     ======================= ================ ================= ============== ================ ================= ==============



     The following  table  outlines items excluded from diluted EPS, as they are
     anti-dilutive (amounts in thousands).

                                                     Quarter Ended
                                                     December 31,
                                                  1999           1998
                                               -----------    -----------
        Options                                       406            383
        Convertible debentures                      1,243          1,243
                                               -----------    -----------
                                                    1,649          1,626
                                               ===========    ===========

     At both  December  31,  1999 and  1998,  the  impact of  assuming  the 1996
     convertible  debentures  were  converted,  net of the  impact of pro forma,
     after tax interest expense, was anti-dilutive.



                                       12






6.   Translation of Foreign Currency:

     Assets  and  liabilities  of  foreign   operations  are  translated   using
     period-end  exchange rates with gains or losses  resulting from translation
     included in a separate component of accumulated other  comprehensive  loss.
     Revenues and expenses are translated using exchange rates prevailing during
     the  period.  Gains and  losses  resulting  from  transactions  in  foreign
     currencies were immaterial.

7.   Comprehensive Income:

     Comprehensive  income is the total of net  income  and all other  non-owner
     changes in equity.  For the  Company,  this  reporting  involves  gains and
     losses  resulting from the translation of assets and liabilities of foreign
     operations  which  are  currently  included  in  a  separate  component  of
     accumulated other  comprehensive loss.  Comprehensive  income for the first
     quarter of fiscal 1999 was $490,000.

8.   Segment Information:

     Meridian operates in two geographic segments:  Meridian  Diagnostics,  Inc.
     (MDI) and Meridian  Diagnostics Europe (MDE). MDI operations consist of the
     manufacture  and sale of  diagnostic  test kits in the U.S.  and  countries
     outside of Europe,  Africa and the Middle East. It also  includes  sales of
     bioresearch  reagents  and  sales of  proficiency  tests,  which  combined,
     represent  approximately  10% of total Company  revenues.  MDE  distributes
     diagnostic  test kits in  Europe,  Africa and the  Middle  East.  Sales are
     attributed  to the  geographic  area based on the  location  from which the
     product is shipped to the customer.

     Segment information for the quarters ended December 31, 1999 and 1998 is as
     follows:

      -------------------------------- --------- -------- ---------- -----------
      ($ in thousands)                    MDI      MDE       ELIM(1)    Total
      -------------------------------- --------- -------- ---------- -----------
      1999
      Net sales                         $12,123   $3,590   ($1,384)    $14,329
      Operating income                    2,552       10        139      2,701
      Income tax provision/(benefit)        899     (42)         48        905
      Net earnings                        1,293       86         91      1,470
      Total assets                       99,838   11,943   (36,667)     75,114
      1998
      Net sales                           9,614    3,286    (1,180)     11,720
      Operating income                    1,338    (198)        260      1,400
      Income tax provision/(benefit)        540     (48)        (9)        483
      Net earnings                          583    (298)        269        554
      Total assets                     $100,974  $12,070  $(40,950)    $72,094

(1)      Eliminations consist of intersegment transactions.


     Transactions  between geographic segments are accounted for as intercompany
     sales at  established  intercompany  prices  for  internal  and  management
     purposes with all intercompany amounts eliminated in consolidation. The MDI
     segment data for total assets includes  corporate  goodwill and intangibles
     of  $23,634,000,  and  $24,349,000 for the quarters ended December 31, 1999
     and 1998 respectively.

9.   Recently Issued Accounting Standards:

     In June 1998, the Financial  Accounting Standards Board issued Statement of
     Financial   Accounting   Standards  No.  133,   Accounting  for  Derivative
     Instruments and Hedging Activities.  The Statement  establishes  accounting
     and  reporting  standards   requiring  that  every  derivative   instrument


                                       13



     (including certain derivative  instruments  embedded in other contracts) be
     recorded in the balance  sheet as either an asset or liability  measured at
     its fair value.  The Company is required to adopt this  statement in fiscal
     year 2001.  The Company does not  currently  hold nor invest in any type of
     derivative instruments.

     In March  1998,  the AICPA  issued SOP 98-1-  "Accounting  for the Costs of
     Computer  Software  Developed or Obtained for Internal Use" which  requires
     capitalization  of external direct costs of materials and services consumed
     in  developing or obtaining  internal-use  computer  software;  payroll and
     payroll-related  costs for employees who are directly  associated  with and
     who devote  time to the  internal-use  computer  software  project  (to the
     extent of the time spent  directly  on the  project);  and  interest  costs
     incurred  when  developing  computer  software for internal  use.  Training
     costs,  data conversion  costs,  costs incurred in the preliminary  project
     stage and  maintenance  fees should be expensed as incurred.  Additionally,
     significant updates and enhancements are capitalized if it is probable that
     the result will be significant  additional  functionality or an increase in
     the life of the software. The capitalization of computer software developed
     or obtained for internal use should be amortized on a  straight-line  basis
     unless another systematic and rational manner is more representative of the
     use of the  software.  The Company  adopted this  accounting  pronouncement
     effective October 1, 1999. The pronouncement has not and is not expected to
     have a material  impact on the  Company's  financial  position or operating
     results.

Item 2. Management's Discussion and Analysis of
        Financial Condition and Results of Operations

Results of Operations:

Net sales  increased  $2,609,000  or 22%, to  $14,329,000  for the first  fiscal
quarter  compared to the prior year.  This  increase  reflects a full quarter of
combined Meridian and Gull sales,  continued growth from core products and up to
an  estimated  $500,000  of  additional  customer  orders,  related to Year 2000
concerns.  This  increase  of  $2,609,000  was  comprised  of  volume  growth of
$3,022,000, or 26%, and currency of $($404,000), or (3%) and price of ($9,000).

Core business product sales were up approximately  19%, while Gull products were
up 30%,  versus the prior year.  These  increases were largely a result of a 25%
increase in the ParaPak  line, an 86% increase in the H. pylori line driven by a
128%  increase  in  Premier  Platinum  HpSA,  and a 29%  increase  in  the  Gull
immunology line. All other focus products experienced growth as well.

International  sales  in  total  were  $4,507,000,  up  $702,000,  or 18%,  from
$3,805,000 compared to the prior year first fiscal quarter.  International sales
represent 32% of total sales in both the first fiscal quarter of 1999 and 1998.

Gross profit increased $1,490,000,  or 20% compared to the sales increase of 22%
and  decreased to 64% of sales from 65% in the prior year fiscal  quarter.  This
nominal  reduction is primarily a result of a higher  percentage of lower margin
Gull sales during the fiscal 2000 first quarter.  The Company  expects this drag
on the overall  gross  profit to continue as the Company  sells-out  Gull's Salt
Lake City inventory over the next two quarters, after which margins are expected
to rebound.

Total operating expenses increased $189,000, or 3%, for the first fiscal quarter
of 2000 versus the prior year, and decreased to 45% of sales from 53% versus the
same period last year,  primarily due to Gull merger  integration costs incurred
in the prior  year.  Excluding  merger  integration  costs,  operating  expenses
increased  $715,000,  or  13%.  Specifically,  research  and  development  costs
decreased  3% to  approximately  $522,000  and  decreased to 4% of sales from 5%
compared  to the same  period  last  year.  The  slight  decrease  reflects  the
consolidation of research and development  activities in the Cincinnati facility
in March of 1999. Selling and marketing expenses increased $276,000, or 10%, for
the first  fiscal  quarter and  decreased  as a percent of sales to 22% from 24%
versus the same period last year. This dollar  increase is primarily  related to
increases in personnel  costs and  expenditures  on  advertising  and  marketing
brochures which  typically  occur in the first quarter.  The decrease in selling


                                       14



and marketing  expenses as a percent of sales reflects the efficiencies  derived
from the  integration  of the Gull line of products into the existing  sales and
marketing organization.  General and administrative costs increased $454,000, or
20%,  for the first  quarter and  decreased to 19% of sales from 20% compared to
the same  period  last year.  This dollar  increase  is  attributable  to higher
amortization  costs  (approximately  $200,000)  based on the final  valuation of
Gull-related  intangibles  and  goodwill  and  having  a full  quarter  of  such
amortization  costs  versus  only two months in the prior  year.  The  remaining
increase is due to  increased  personnel  costs,  depreciation  expense for Gull
related  assets (three months this quarter versus two months in the same quarter
last year) and  increases  in the reserve  for  doubtful  accounts.  The Company
incurred merger  integration  costs of  approximately  $526,000 during the first
fiscal  quarter of 1999 in  connection  with the Gull  acquisition.  These costs
consisted  mainly of payments  of $275,000  made to  distributors  to  terminate
contracts in markets with  duplicate  distributor  agreements or in markets that
are now covered by the Company sales force, and  approximately  $250,000 related
to training and travel in connection  with the integration of the Gull business.
Merger  integration  costs were  immaterial for the first fiscal quarter of 2000
and are expected to remain so for the balance of the fiscal year.

Operating income as a result of the above increased  $1,301,000,  or 93% for the
first fiscal  quarter and  increased as a percent of sales to 19% from 12%. Even
excluding  first  quarter of fiscal 1999 merger  integration  costs of $526,000,
operating  income  for the first  fiscal  quarter  increased  $775,000,  or 40%,
compared to the same quarter in the prior year. Other expense  decreased $37,000
for the first fiscal quarter.  Lower  investment  income as a result of the cash
used  to  acquire  Gull  was  offset  by  lower  interest  expenses  due  to the
refinancing  and  reductions  in  Gull-related  debt that occurred in the second
quarter of fiscal year 1999. The Company's effective tax rate decreased from 47%
to 38%. The Company has recorded a benefit for the full amount of first  quarter
fiscal 2000 losses incurred in Gull's foreign  operations  based on tax planning
strategies  developed  to utilize such  losses.  In the first  quarter of fiscal
1999,  losses from the Gull European  operations were not fully benefited as tax
planning strategies were being developed.

Liquidity and Capital Resources

The Company prepares annual operating and capital  spending  budgets.  These two
items, along with acquisition  plans, are analyzed to determined  operating cash
flow and  potential  financing  needs.  The  Company  historically  maintains  a
significant  level of cash and cash  equivalents and  availability on its credit
facility so that it can quickly respond to acquisition opportunities.

In the first quarter of fiscal 2000, net cash flows of $1,432,000  were provided
by operations  compared to  $5,620,000  for the first quarter of the prior year.
The  amount  of cash  provided  by  operating  activities  decreased  $4,188,000
compared to the first quarter of the prior year due to the reduction in accounts
receivables  in the first  quarter  of fiscal  1999 as a result  of  changes  in
distributor  order  patterns  that  occurred in the second half of fiscal  1998.
Additionally,  amounts  related to merger  activities  were accrued in the first
quarter of the prior year, while such amounts were paid in succeeding  quarters,
including the first quarter of fiscal 2000.

Net cash used for investing  activities  of $1,290,000  decreased as a result of
the purchase of Gull in the first quarter of fiscal 1999.  Capital  expenditures
increased  over the same period in the prior year due to the  renovations to the
Cincinnati facility to accommodate the Gull product line.

Net cash flows provided by financing  activities were $2,774,000 compared to net
cash  used in  financing  activities  of  $1,558,000  in the  prior  year.  This
fluctuation  is  largely  due  to  reductions  in  Gull-related   debt  payments
subsequent to the  refinancing  of Gull debt that occurred in the second quarter
of fiscal  1999.  Additionally,  in  December  1999,  the Company  financed  the
renovations of the  Cincinnati  facilities  through a $3,478,000  five-year term
loan bearing interest at an 8 % rate, and a $522,000 seven-year capital lease.


                                       15



Net  cash  flows  from  operations  are  anticipated  to  fund  working  capital
requirements  for the balance of the fiscal year.  The Company has a $20,000,000
credit facility with a commercial bank under which  $12,646,000 is available and
cash and cash  equivalent and short-term  investments of $10,034,000 at December
31, 1999.

Impact of Year 2000

Prior to December 31, 1999, the Company  implemented plans to ready all critical
information   technology   systems,   including   hardware  and  software,   and
non-information   technology  systems,   such  as  computer  chips  embedded  in
communication,   security,   manufacturing,   laboratory   and   instrumentation
equipment.  As of the date of this  filing,  the Company has had no  significant
interruptions  to its  business  as a result of the Year 2000 date  change.  The
Company plans to monitor its information  technology systems and non-information
technology  systems  throughout  fiscal 2000 to identify  and address any issues
related to the Year 2000 date change.

The Company is also in the process of assessing the impact of the  conversion to
the Euro on its systems and business operations.  The Company's primary business
locations in Europe are currently able to process Euro transactions. The Company
does not believe this conversion will have a material impact on the business and
operations, however, there can be no assurances that this will be the case.





                                       16





PART II.  OTHER INFORMATION

Item 5.  Other Information

The Company  announced on October 22, 1999,  that the United  States Health Care
Financing   Administration  (HCFA)  announced  their  national  coverage  policy
decision  relating to our Premier  Platinum  HpSA(TM)  (HpSA)  test.  HpSA has a
separate  CPT code of 87338 that became  active in January,  2000.  After HCFA's
analysis of the medical evidence  submitted by Meridian  Diagnostics,  including
recent peer-reviewed publications, HCFA indicated that the new non-invasive HpSA
test has a potential  and vital role in the daily  management  of patients  with
Peptic Ulcer Disease (PUD) and those with suspected and/or  documented H. pylori
infection.

Item 6.   Exhibits and Reports on Form 8-K

(a)      Exhibits:

           Exhibit No.                 Description                     Page(s)
           -----------        ----------------------------------       -------
           27                 Financial Data Schedule (Restated)       17-19
           99                 Forward Looking Statements               20

(b)      Reports on Form 8-K:

            None.




                                       17




Signature:

         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
         the  Registrant  has duly caused this report to be signed on its behalf
         by the undersigned there-unto duly authorized.

                                        MERIDIAN DIAGNOSTICS, INC.
                                        AND SUBSIDIARIES


      Date:  August 4, 2000              /S/     Melissa Lueke
                                        ----------------------------------------
                                         Melissa Lueke
                                         Corporate Controller
                                         (Acting Principal Financial Officer)