<PAGE>   1
 
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                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
 
                             ---------------------
 
                                   FORM 10-Q
 
                             ---------------------
 
(MARK ONE)
 
   [X]          QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
 
                  FOR THE QUARTERLY PERIOD ENDED JUNE 30, 1998
 
                                       OR
 
   [ ]         TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D)
                         OF THE SECURITIES ACT OF 1934
 
                         COMMISSION FILE NUMBER 0-19946
 
                             LINCARE HOLDINGS INC.
             (Exact name of registrant as specified in its charter)
 
<TABLE>
  <S>                                                      <C>
                   DELAWARE                                      51-0331330
       (State or other jurisdiction of                        (I.R.S. Employer
        incorporation or organization)                      Identification No.)
 
        19337 US 19 NORTH, SUITE 500,                              33764
                CLEARWATER, FL                                   (Zip Code)
   (Address of principal executive offices)
</TABLE>
 
      Registrant's telephone number, including area code:  (813) 530-7700
 
     Indicate by 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.
 
<TABLE>
<CAPTION>
                           CLASS                              OUTSTANDING AT JULY 31, 1998
                           -----                              -----------------------------
<S>                                                           <C>
Common Stock, $0.01 par value...............................        58,077,932 shares
</TABLE>
 
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<PAGE>   2
 
                             LINCARE HOLDINGS INC.
 
                                   FORM 10-Q
                  FOR THE QUARTERLY PERIOD ENDED JUNE 30, 1998
 
                                     INDEX
 
<TABLE>
<CAPTION>
                                                                      PAGE
                                                                      ----
<S>     <C>                                                           <C>
PART I.  FINANCIAL INFORMATION

Item 1   Financial Statements (unaudited)
         Condensed consolidated balance sheets.......................    3
         Condensed consolidated statements of operations.............    4
         Condensed consolidated statements of cash flows.............    5
         Notes to condensed consolidated financial statements........    6

Item 2   Management's Discussion and Analysis of Results of
         Operations and Financial Condition..........................    7

Item 3   Quantitative and Qualitative Disclosure Regarding Market
         Risk........................................................    9
 
PART II. OTHER INFORMATION

Item 1   Legal Proceedings...........................................    9

Item 2   Changes in Securities.......................................   10

Item 3   Defaults Upon Senior Securities.............................   10

Item 4   Submission of Matters to a Vote of the Security Holders.....   10

Item 6   Exhibits and Reports on Form 8-K............................   10
 
SIGNATURE...........................................................    11
</TABLE>
 
                                        2
<PAGE>   3
 
                     LINCARE HOLDINGS INC. AND SUBSIDIARIES
 
                     CONDENSED CONSOLIDATED BALANCE SHEETS
 
<TABLE>
<CAPTION>
                                                               JUNE 30,      DECEMBER 31,
                                                                 1998            1997
                                                              -----------    ------------
                                                              (UNAUDITED)
                                                                    (IN THOUSANDS)
<S>                                                           <C>            <C>
                                         ASSETS
Current assets:
  Cash and cash equivalents.................................   $  5,980        $  4,078
  Accounts and notes receivable.............................     75,464          68,383
  Income tax receivable.....................................     10,352           2,530
  Inventories...............................................      1,818           1,542
  Prepaid expenses..........................................        595             516
                                                               --------        --------
          Total current assets..............................     94,209          77,049
                                                               --------        --------
Property and equipment......................................    212,561         181,438
Less: accumulated depreciation..............................     89,532          73,148
                                                               --------        --------
          Net property and equipment........................    123,029         108,290
                                                               --------        --------
Other assets:
  Goodwill..................................................    279,575         245,600
  Intangible assets.........................................      5,296           5,262
  Covenants not to compete..................................      2,315           2,869
  Other.....................................................      1,283           1,318
                                                               --------        --------
          Total other assets................................    288,469         255,049
                                                               --------        --------
               Total assets.................................   $505,707        $440,388
                                                               ========        ========
 
                          LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Current installments of long-term obligations.............   $ 11,044        $  8,580
  Accounts payable..........................................     16,990          14,390
  Accrued expenses:
     Compensation and benefits..............................     10,087           8,781
     Other..................................................      4,648           3,192
                                                               --------        --------
          Total current liabilities.........................     42,769          34,943
                                                               --------        --------
Long-term obligations, excluding current installments.......      8,439           4,602
Deferred income taxes.......................................     10,537           6,861
Minority interest...........................................        800             915
Stockholders' equity:
  Common stock..............................................        582             574
  Additional paid-in capital................................    122,970         110,714
  Retained earnings.........................................    320,681         281,779
  Less: treasury stock......................................      1,071              --
                                                               --------        --------
          Total stockholders' equity........................    443,162         393,067
                                                               --------        --------
               Total liabilities and stockholders' equity...   $505,707        $440,388
                                                               ========        ========
</TABLE>
 
     See accompanying notes to condensed consolidated financial statements.
 
                                        3
<PAGE>   4
 
                     LINCARE HOLDINGS INC. AND SUBSIDIARIES
 
                CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                            FOR THE THREE MONTHS ENDED         FOR THE SIX MONTHS ENDED
                                          -------------------------------   -------------------------------
                                             JUNE 30,         JUNE 30,         JUNE 30,         JUNE 30,
                                               1998             1997             1998             1997
                                          --------------   --------------   --------------   --------------
                                          (IN THOUSANDS EXCEPT SHARE AND    (IN THOUSANDS EXCEPT SHARE AND
                                                  PER SHARE DATA)                   PER SHARE DATA)
<S>                                       <C>              <C>              <C>              <C>
Net revenues............................   $    119,518     $    108,702     $    231,422     $    209,714
                                           ------------     ------------     ------------     ------------
Costs and expenses:
  Costs of goods and services...........         18,681           16,527           36,700           31,944
  Operating expenses....................         27,643           22,966           54,283           44,506
  Selling, general and administrative
     expenses...........................         26,647           21,879           52,119           42,349
  Bad debt expense......................          1,434            1,092            2,777            2,097
  Depreciation expense..................          8,565            6,620           16,575           12,935
  Amortization expense..................          2,966            3,623            5,951            7,063
                                           ------------     ------------     ------------     ------------
                                                 85,936           72,707          168,405          140,894
                                           ------------     ------------     ------------     ------------
          Operating income..............         33,582           35,995           63,017           68,820
                                           ------------     ------------     ------------     ------------
Other income (expense):
  Interest income.......................            159               39              284               67
  Interest expense......................           (129)            (475)            (216)            (701)
  Net loss on disposal of property and
     equipment..........................            (23)             (40)             (34)             (59)
                                           ------------     ------------     ------------     ------------
                                                      7             (476)              34             (693)
                                           ------------     ------------     ------------     ------------
          Income before income taxes....         33,589           35,519           63,051           68,127
Income taxes............................         12,865           13,676           24,149           26,229
                                           ------------     ------------     ------------     ------------
          Net income....................   $     20,724     $     21,843     $     38,902     $     41,898
                                           ============     ============     ============     ============
Income per common share.................
  Basic.................................   $       0.36     $       0.39     $       0.67     $       0.74
                                           ============     ============     ============     ============
  Diluted...............................   $       0.35     $       0.37     $       0.66     $       0.72
                                           ============     ============     ============     ============
Weighted average number of common shares
  outstanding...........................     57,960,693       56,715,444       57,771,955       56,656,420
                                           ============     ============     ============     ============
Weighted average number of common shares
  and common share equivalents
  outstanding...........................     59,365,322       58,362,052       59,392,340       58,269,818
                                           ============     ============     ============     ============
</TABLE>
 
     See accompanying notes to condensed consolidated financial statements.
 
                                        4
<PAGE>   5
 
                     LINCARE HOLDINGS INC. AND SUBSIDIARIES
 
                CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                              FOR THE SIX MONTHS ENDED
                                                              ------------------------
                                                              JUNE 30,       JUNE 30,
                                                                1998           1997
                                                              ---------      ---------
                                                                   (IN THOUSANDS)
<S>                                                           <C>            <C>
Cash from operations........................................  $ 63,599       $ 52,602

Investing activities:
  Proceeds from sale of property and equipment..............        68            102
  Capital expenditures......................................   (29,865)       (24,901)
  Decrease in other assets..................................        35             35
  Business acquisitions, net of cash acquired...............   (34,784)       (45,094)
                                                              --------       --------
                                                               (64,546)       (69,858)
                                                              --------       --------
Financing activities:
  Proceeds from long-term obligations.......................    18,000         53,000
  Payment of long-term obligations..........................   (19,887)       (35,949)
  Decrease in minority interest.............................      (253)          (244)
  Proceeds from issuance of common stock....................     6,060          1,493
  Payment to acquire treasury stock.........................    (1,071)            --
                                                              --------       --------
                                                                 2,849         18,300
                                                              --------       --------
Increase in cash............................................     1,902          1,044
Cash and cash equivalents, beginning of period..............     4,078          1,541
                                                              --------       --------
Cash and cash equivalents, end of period....................  $  5,980       $  2,585
                                                              ========       ========
</TABLE>
 
     See accompanying notes to condensed consolidated financial statements.
 
                                        5
<PAGE>   6
 
                             LINCARE HOLDINGS INC.
 
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                                  (UNAUDITED)
 
NOTE 1 -- BASIS OF PRESENTATION
 
     The accompanying condensed consolidated balance sheet as of June 30, 1998,
the condensed consolidated statements of operations for the three months ended
June 30, 1998 and 1997 and for the six months ended June 30, 1998 and 1997 and
the condensed consolidated statements of cash flows for the six months ended
June 30, 1998 and 1997 are unaudited. In the opinion of management, all
adjustments, consisting of normal recurring accruals, necessary for a fair
presentation of the results of operations for the interim periods presented have
been reflected herein. The results of operations for interim periods are not
necessarily indicative of the results to be expected for the entire year. The
accompanying condensed consolidated balance sheet as of December 31, 1997 is
derived from the Lincare Holdings Inc. (the "Company") audited balance sheet as
of that date.
 
NOTE 2 -- BUSINESS COMBINATIONS
 
     During the six months ended June 30, 1998 the Company acquired, in
unrelated acquisitions, the stock of nine companies and certain assets of six
companies. Each acquisition was accounted for as a purchase. The results of the
acquired companies are included in the accompanying consolidated statements of
operations since the respective date of acquisition.
 
     The aggregate cost of these acquisitions was as follows:
 
<TABLE>
<CAPTION>
                                                              (IN THOUSANDS)
                                                              --------------
<S>                                                           <C>
Cash (including cash acquired of $546)......................     $35,330
Deferred acquisition obligations............................       8,109
Assumption of liabilities...................................         155
                                                                 -------
                                                                 $43,594
                                                                 =======
</TABLE>
 
     The aggregate purchase price was allocated as follows:
 
<TABLE>
<S>                                                           <C>
Current assets..............................................     $ 2,294
Property and equipment......................................       1,551
Intangible assets...........................................       1,992
Goodwill....................................................      37,757
                                                                 -------
                                                                 $43,594
                                                                 =======
</TABLE>
 
     Unaudited pro forma supplemental information on the results of operations
for the six months ended June 30, 1998 and June 30, 1997 are provided below and
reflect the acquisitions as if they had been combined at the beginning of each
respective period.
 
<TABLE>
<CAPTION>
                                                              FOR THE SIX MONTHS ENDED
                                                                      JUNE 30,
                                                              ------------------------
                                                                1998           1997
                                                              ---------      ---------
                                                               (IN THOUSANDS, EXCEPT
                                                                  PER SHARE DATA)
<S>                                                           <C>            <C>
Net revenues................................................  $246,499       $218,418
                                                              ========       ========
Net income..................................................  $ 41,735       $ 43,517
                                                              ========       ========
Income per common share
  Basic.....................................................  $    .72       $    .77
                                                              ========       ========
  Diluted...................................................  $    .70       $    .75
                                                              ========       ========
</TABLE>
 
     The unaudited pro forma financial information is not necessarily indicative
of either the results of operations that would have occurred had the
transactions been effected at the beginning of the respective preceding periods
or of future results of operations of the combined companies.
 
                                        6
<PAGE>   7
 
                             LINCARE HOLDINGS INC.
 
                    MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                 RESULTS OF OPERATIONS AND FINANCIAL CONDITION
 
OPERATING RESULTS
 
     The following table sets forth for the periods indicated a summary of the
Company's net revenues by source:
 
<TABLE>
<CAPTION>
                                          FOR THE THREE MONTHS    FOR THE SIX MONTHS ENDED
                                             ENDED JUNE 30,               JUNE 30,
                                          --------------------    ------------------------
                                            1998        1997         1998          1997
                                          --------    --------    ----------    ----------
                                             (IN THOUSANDS)            (IN THOUSANDS)
<S>                                       <C>         <C>         <C>           <C>
Oxygen and other respiratory therapy....  $107,157    $ 96,772     $207,145      $188,222
Home medical equipment and other........    12,361      11,930       24,277        21,492
                                          --------    --------     --------      --------
          Total.........................  $119,518    $108,702     $231,422      $209,714
                                          ========    ========     ========      ========
</TABLE>
 
     On August 5, 1997, the Balanced Budget Act of 1997 ("BBA") was signed into
law. The legislation, among other things, reduces Medicare expenditures by $115
billion over five years. The BBA reduces Medicare payment amounts for oxygen and
oxygen equipment furnished after January 1, 1998, to 75 percent of the fee
schedule amounts in effect during 1997. Payment amounts for oxygen and oxygen
equipment furnished after January 1, 1999, and each subsequent year are reduced
to 70 percent of the fee schedule amounts in effect during 1997.
 
     The BBA freezes the Consumer Price Index (U.S. urban average) update for
covered items of durable medical equipment for each of the years 1998 through
2002 while limiting fees for parenteral and enteral nutrients, supplies and
equipment to 1995 reasonable charge levels over the same period. The BBA reduces
payment amounts for covered drugs and biologicals to 95 percent of the average
wholesale price of such covered items for each of the years 1998 through 2002.
 
     The BBA authorizes the Department of Health and Human Services to conduct
up to five competitive bidding demonstration projects for the acquisition of
durable medical equipment and requires that one such project be established for
oxygen and oxygen equipment. Each demonstration project is to be operated over a
three-year period and is to be conducted in not more than three competitive
acquisition areas. The BBA also includes provisions designated to reduce health
care fraud and abuse including a surety bond requirement for durable medical
equipment providers.
 
     On August 10, 1993, Congress passed the Omnibus Reconciliation Act of 1993
("OBRA 93"). The OBRA 93 legislation provided for a consumer price index update,
effective January 1, 1997, of approximately 2.8% on Medicare products and
services. There was no impact from OBRA 93 in 1998.
 
     Net revenues for the three months ended June 30, 1998 increased by
$10,816,000 (or 10.0%) compared with the three months ended June 30, 1997, and
for the six months ended June 30, 1998 increased 21,708,000 (or 10.3%) compared
with the six months ended June 30, 1997. The price cuts attributable to the BBA
reduced the Company's revenues by approximately $17,085,000 and $32,538,000 for
the three and six months ended June 30, 1998. (see table)
 
<TABLE>
<CAPTION>
                                    FOR THE THREE MONTHS                 FOR THE SIX MONTHS
                                       ENDED JUNE 30,       PERCENTAGE     ENDED JUNE 30,      PERCENTAGE
                                    ---------------------    INCREASE    -------------------    INCREASE
                                      1998        1997      (DECREASE)     1998       1997     (DECREASE)
                                    ---------   ---------   ----------   --------   --------   ----------
                                       (IN THOUSANDS)                      (IN THOUSANDS)
<S>                                 <C>         <C>         <C>          <C>        <C>        <C>
Revenues -- before price cuts.....  $136,603    $108,702       25.7      $263,960   $209,714      25.8
Effect of price cuts..............   (17,085)         --      (15.7)      (32,538)        --     (15.5)
                                    --------    --------      -----      --------   --------     -----
Actual revenues...................  $119,518    $108,702       10.0      $231,422   $209,714      10.3
                                    ========    ========      =====      ========   ========     =====
</TABLE>
 
     Excluding the effect on the Company's revenues from the Medicare price
reductions, internally generated growth increased revenues by approximately
$17,575,000 (or 16.2%) for the three months ended June 30, 1998 and $32,546,000
(or 15.5%) for the six months ended June 30, 1998.
 
                                        7
<PAGE>   8
 
     Excluding the effect on the Company's revenues from the Medicare price
reductions, growth due to acquisitions increased revenues by approximately
$10,326,000 (or 9.5%) for the three months ended June 30, 1998 and $21,700,000
(or 10.3%) for the six months ended June 30, 1998.
 
     The revenue price cuts attributed to the BBA affected the relationship of
costs and expenses expressed as a percentage of net revenues. (see table)
 
<TABLE>
<CAPTION>
                                             EXPRESSED AS A PERCENTAGE OF NET REVENUES
                          -------------------------------------------------------------------------------
                                FOR THE THREE MONTHS ENDED                FOR THE SIX MONTHS ENDED
                          --------------------------------------   --------------------------------------
                                         RESULTS                                  RESULTS
                                        EXCLUDING                                EXCLUDING
                           ACTUAL     IMPACT OF BBA     ACTUAL      ACTUAL     IMPACT OF BBA     ACTUAL
                           RESULTS      PRICE CUTS      RESULTS     RESULTS      PRICE CUTS      RESULTS
                          JUNE 30,       JUNE 30,      JUNE 30,    JUNE 30,       JUNE 30,      JUNE 30,
                            1998           1998          1997        1998           1998          1997
                          ---------   --------------   ---------   ---------   --------------   ---------
<S>                       <C>         <C>              <C>         <C>         <C>              <C>
Costs of goods and
  services..............    15.6%          13.7%         15.2%       15.9%          13.9%         15.2%
Operating expense.......    23.1%          20.2%         21.1%       23.5%          20.6%         21.2%
Selling, general and
  administrative
  expense...............    22.3%          19.5%         20.1%       22.5%          19.7%         20.2%
</TABLE>
 
     Costs of goods and services as a percentage of net revenues was 15.6% for
the three months ended June 30, 1998 compared with 15.2% for the three months
ended June 30, 1997. Costs of goods and services as a percentage of net revenues
were 15.9% for the six months ended June 30, 1998 compared with 15.2% for the
six months ended June 30, 1997. Absent the effect of the BBA price cuts, cost of
goods as a percentage of net revenues was 13.7% for the three months ended June
30, 1998 and 13.9% for the six months ended June 30, 1998. This improvement is
attributed primarily to the maturity of the Company's respiratory pharmacy
operations which commenced operations in the fourth quarter of 1996 as well as
increased revenues from rental of capital equipment.
 
     Operating expenses as a percentage of net revenues were 23.1% for the three
months ended June 30, 1998 as compared to 21.1% for the three months ended June
30, 1997. Operating expenses as a percentage of net revenues were 23.5% for the
six months ended June 30, 1998 compared with 21.2% for the six months ended June
30, 1997. Adjusted to remove the effect of the BBA price cuts, operating
expenses as a percentage of net revenues were 20.2% for the three months ended
June 30, 1998 and 20.6% for the six months ended June 30, 1998. This improvement
was primarily due to the Company's successful integration of acquired businesses
into its existing locations.
 
     Selling, general and administrative expenses as a percentage of net
revenues were 22.3% for the three months ended June 30, 1998 compared with 20.1%
for the three months ended June 30, 1997. Selling, general and administrative
expenses as a percentage of net revenues were 22.5% for the six months ended
June 30, 1998 compared with 20.2% for the six months ended June 30, 1997.
Expressed as a percentage of net revenues before the price cuts attributed to
the BBA, selling, general and administrative expenses were 19.5% for the three
months ended June 30, 1998 and 19.7% for the six months ended June 30, 1998. The
company has been able to maintain a cost structure that, with increases in net
revenues, allows the Company to spread its overhead across a larger base of
revenue, resulting in improvements in operating income.
 
     Amortization expense for the three months ended June 30, 1998 decreased to
$2,966,000 compared with $3,623,000 for the three month period ending June 30,
1997. Amortization expense for the six months ended June 30, 1998 decreased to
$5,951,000 compared with $7,063,000 for the six month period ended June 30,
1997. The decrease is attributable to the impairment writedown of certain
customer list intangible assets in the fourth quarter of 1997.
 
     Operating income for the three and six months ended June 30, 1998 decreased
to $33,582,000 and $63,017,000, respectively, compared with $35,995,000 and
$68,820,000 for the three and six months ended June 30, 1997. These decreases
are due to the impact of the revenue price cuts attributable to the BBA.
 
                                        8
<PAGE>   9
 
LIQUIDITY AND CAPITAL RESOURCES
 
     Net cash provided from operating activities was $63,599,000 for the six
months ended June 30, 1998 compared with $52,602,000 for the six months ended
June 30, 1997. The increase in cash from operating activities is primarily
attributed to improved management of working capital. Accounts receivable
increased $4,202,000 for the six months ended June 30, 1998 compared with an
increase of $6,665,000 for the six months ended June 30, 1997. Accounts payable
increased $2,600,000 for the six months ended June 30, 1998 compared with a
decrease of $5,102,000 for the six months ended June 30, 1997.
 
     Net cash used in investing and financing activities was $61,697,000 for the
six months ended June 30, 1998 compared with $51,558,000 for the six months
ended June 30, 1997. First and second quarter activity included the Company's
investment of $34,784,000 in business acquisitions, investment in capital
equipment of $29,865,000, proceeds of $18,000,000 from long-term obligations,
payments of $19,887,000 related to long-term obligations, and proceeds from
common stock issued of $6,060,000 related to the exercise of employee stock
options.
 
     Effective May 14, 1998, the Board of Directors declared a two-for-one stock
split in the form of a 100% stock dividend, which was paid on May 29, 1998 to
stockholders of record on May 15, 1998. In connection with the stock split, the
Company increased the number of shares of Common Stock authorized from 50
million to 200 million, which increase was approved by the stockholders of the
Company at the Annual Meeting held in May, 1998. The par value of the additional
28,988,216 shares of Common Stock issued by reason of the stock split was
credited to Common Stock and a like amount charged to paid-in-capital. All share
and per share data included in the Company's condensed consolidated financial
statements has been adjusted for all periods presented to reflect the stock
split.
 
QUANTITATIVE AND QUALITATIVE DISCLOSURE REGARDING MARKET RISK
 
     The Company has no derivative securities as of June 30, 1998. The Company
is exposed to changes in interest rates as a result of its bank credit facility
which is based on the London Interbank Offered Rate.
 
     A 10% increase in interest rates related to the Company's bank credit
facility would not have a material effect on the Company's earnings over the
next fiscal year.
 
FORWARD LOOKING STATEMENTS
 
     Statements contained in this Form 10-Q that are not based on historical
facts are forward looking statements, subject to uncertainties and risks,
including, but not limited to, the constantly changing healthcare environment,
potential reductions in reimbursement by government and third party payors for
the Company's products and services, the demand for Company's products and
services, economic and competitive conditions, the availability of appropriate
acquisition candidates and the successful completion of acquisitions, access to
borrowed and/or equity capital on favorable terms, and other risks detailed in
the Company's Securities and Exchange Commission filings.
 
PART II.  OTHER INFORMATION
 
Item 1  Legal Proceedings
 
     The Company has received subpoenas from the U.S. Attorney's Office in
Sacramento, California requesting various documents including (i) documents
relating to the provision of home oxygen therapy to beneficiaries of certain
federally funded healthcare programs during 1995 and 1996 by five Lincare
locations in California and Oregon; (ii) documents concerning certain marketing
programs and practices for oxygen and other therapies, and certain policies and
procedures, in place at five Lincare locations in California and Oregon from
1995 to present; and (iii) certain information regarding compliance with the
billing and documentation requirements of various federally funded health care
programs by ten Lincare locations in California and Oregon from 1995 to present.
 
                                        9
<PAGE>   10
 
     The federal government has not served the Company with a complaint nor has
it disclosed the basis for its inquiries to the Company. The Company is
cooperating with the government's request for information. Due to its
preliminary nature, the duration or outcome of this matter cannot be predicted
with any degree of certainty.
 
Items 2-3  Not applicable.
 
Item 4  Submission of Matters to a Vote of the Security Holders.
 
     The Annual Meeting of Shareholders of the Company was held on May 11, 1998.
The following matters were voted on at the Annual Meeting, with the number of
votes cast for, against or withheld, in each case, as applicable, indicated next
to each such matter:
 
          1. Election of directors:
 
<TABLE>
<CAPTION>
                                                                 FOR       WITHHELD
                                                              ----------   --------
<S>                                                           <C>          <C>
J. T. Kelly.................................................  25,527,022    81,163
J. P. Byrnes................................................  25,526,922    81,263
A. M. Paul..................................................  25,527,022    81,163
C. B. Black.................................................  25,527,022    81,163
F. T. Cary..................................................  25,526,422    81,763
T. O. Pyle..................................................  25,527,022    81,163
W. F. Miller, III...........................................  25,527,022    81,163
</TABLE>
 
          2. Ratification of the selection of KPMG Peat Marwick LLP as the
     Company's independent accountants for the fiscal year ending December 31,
     1998:
           For: 25,602,124       Against: 2,086       Abstain: 3,975
 
          3. Approval of the Company's Employee Stock Purchase Plan:
           For: 25,178,215       Against: 402,545       Abstain: 27,425
 
          4. Approval of the Company's 1998 Stock Plan:
           For: 21,091,152       Against: 4,489,775       Abstain: 27,258
 
          5. Approval of the Company's Amended and Restated Certificate of
     Incorporation:
           For: 14,850,270       Against: 6,175,353       Abstain: 71,925
           Broker Non-Vote: 4,949,451
 
Item  6    Exhibits and Reports on Form 8-K
 
     (a) Exhibits:
 
<TABLE>
<CAPTION>
                                                                             SEQUENTIALLY
EXHIBIT                                                                        NUMBERED
NUMBER                                   EXHIBIT                                 PAGE
-------                                  -------                             ------------
<C>       <C>  <S>                                                           <C>
  3.1     --   Amended and Restated Certificate of Incorporation of Lincare
               Holdings Inc................................................
3.1.1     --   Certificate of Amendment to the Amended and Restated
               Certificate of Incorporation of Lincare Holdings Inc........
 27.0     --   Financial Data Schedule (for SEC Use Only)..................
</TABLE>
 
     (b) The Company did not file a Current Report on Form 8-K during the six
months ended June 30, 1998.
 
                                       10
<PAGE>   11
 
                                   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 thereunto duly authorized.
 
                                                  Lincare Holdings Inc.
                                          --------------------------------------
                                                        Registrant
 
                                                    /s/  PAUL G. GABOS
                                          --------------------------------------
                                                      Paul G. Gabos
                                            Secretary, Chief Financial Officer
                                             and Principal Accounting Officer
 
August 12, 1998
 
                                       11