<PAGE>   1

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 10-Q

[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
        Exchange Act of 1934

For the transition period from ____________to____________

                         Commission file number 0-19903


                                 METRICOM, INC.
                            (A Delaware Corporation)
                   I.R.S. Employer Identification #77-0294597

                              980 University Avenue
                            Los Gatos, CA 95032-2375
                                 (408) 399-8200


         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 [ ]

                      The number of shares of common stock
                outstanding as of July 31, 1998 was 18,624,722



<PAGE>   2



                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                              PAGE
<S>                                                                           <C>
PART I.           FINANCIAL INFORMATION

         ITEM 1.  FINANCIAL STATEMENTS

                  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 FINANCIAL CONDITION
                    AND RESULTS OF OPERATIONS

                  Results of Operations                                          9

                  Liquidity and Capital Resources                               11

PART II. OTHER INFORMATION

         ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS           12
         ITEM 5.  OTHER INFORMATION                                             13
         ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K                              13

SIGNATURE PAGE                                                                  14

EXHIBIT INDEX                                                                   15

</TABLE>


2
<PAGE>   3





PART I.           FINANCIAL INFORMATION

         ITEM 1.        FINANCIAL STATEMENTS

                         METRICOM, INC. AND SUBSIDIARIES
                      CONDENSED CONSOLIDATED BALANCE SHEETS
                                 (IN THOUSANDS)
<TABLE>
<CAPTION>
                                                                       JUNE 30,       DECEMBER 31,
                                                                         1998              1997
                                                                       ---------         ---------
                                     ASSETS
<S>                                                                    <C>               <C>      
CURRENT ASSETS:
  Cash and cash equivalents ...................................        $  41,147         $   9,784
  Short-term investments ......................................              150             4,390
  Accounts receivable, net ....................................            2,513             2,278
  Inventories .................................................            4,837             3,011
  Prepaid expenses and other ..................................            2,265             1,124
                                                                       ---------         ---------
      Total current assets ....................................           50,912            20,587
PROPERTY AND EQUIPMENT, net ...................................           22,927            25,875
LONG-TERM INVESTMENTS .........................................               58               300
OTHER ASSETS, net .............................................            3,309             4,341
                                                                       ---------         ---------
      Total assets ............................................        $  77,206         $  51,103
                                                                       =========         =========

                 LIABILITIES AND STOCKHOLDERS' EQUITY (DEFICIT)
CURRENT LIABILITIES:
  Accounts payable ............................................        $   3,502         $   3,143
  Accrued liabilities .........................................            7,180             5,464
  Note payable ................................................               --             5,000
                                                                       ---------         ---------
      Total current liabilities ...............................           10,682            13,607
                                                                       ---------         ---------

LONG-TERM DEBT ................................................           45,000            45,000
                                                                       ---------         ---------
OTHER LIABILITIES .............................................              943             1,129
                                                                       ---------         ---------
MINORITY INTEREST .............................................            5,184             5,184
                                                                       ---------         ---------

STOCKHOLDERS' EQUITY (DEFICIT):
  Common stock ................................................               19                14
  Additional paid-in capital ..................................          189,605           135,466
  Unrealized holding gain on investments ......................                5                 1
  Accumulated deficit .........................................         (174,232)         (149,298)
                                                                       ---------         ---------
      Total stockholders' equity (deficit) ....................           15,397           (13,817)
                                                                       ---------         ---------
      Total liabilities and stockholders' equity (deficit) ....        $  77,206         $  51,103
                                                                       =========         =========
</TABLE>

         The accompanying notes are an integral part of these condensed
                            consolidated statements.


3
<PAGE>   4






                         METRICOM, INC. AND SUBSIDIARIES
                 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<TABLE>
<CAPTION>

                                                    THREE MONTHS ENDED               SIX MONTHS ENDED
                                                    ------------------               ----------------
                                            JUNE 30, 1998     JUNE 30, 1997   JUNE 30, 1998    JUNE 30, 1997
                                            -------------     -------------   -------------    -------------
<S>                                         <C>               <C>             <C>              <C>  
REVENUES:
  Service revenues ....................        $  2,277         $  2,209         $  4,251            3,373
  Product revenues ....................           2,084            2,533            3,713            3,163
                                               --------         --------         --------         --------
      Total revenues ..................           4,361            4,742            7,964            6,536
                                               --------         --------         --------         --------

COSTS AND EXPENSES:
  Cost of service revenues ............           7,564            6,792           13,722           13,674
  Cost of product revenues ............           1,416            1,412            2,791            1,687
  Research and development ............           3,715            2,868            6,773            5,889
  Selling, general and
     administrative ...................           4,605            5,387            8,866           10,764
  Provision for Overall Wireless ......              --            3,611               --            3,611
                                               --------         --------         --------         --------

  Total costs and expenses ............          17,300           20,070           32,152           35,625
                                               --------         --------         --------         --------

    Loss from operations ..............         (12,939)         (15,328)         (24,188)         (29,089)

INTEREST EXPENSE ......................             953            1,172            1,965            2,131
INTEREST INCOME .......................             671              549            1,224            1,310
                                               --------         --------         --------         --------

    Net loss ..........................        $(13,221)        $(15,951)        $(24,929)        $(29,910)
                                               ========         ========         ========         ========

BASIC & DILUTED
  NET LOSS PER SHARE..................         $  (0.71)        $  (1.17)        $  (1.41)        $  (2.20)
                                               ========         ========         ========         ========

WEIGHTED AVERAGE
  SHARES OUTSTANDING ..................          18,512           13,601           17,728           13,591
                                               ========         ========         ========         ========
</TABLE>





         The accompanying notes are an integral part of these condensed
                            consolidated statements.



4
<PAGE>   5



                         METRICOM, INC. AND SUBSIDIARIES
                 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
<TABLE>
<CAPTION>

                                                                            SIX MONTHS ENDED
                                                                          JUNE 30,         JUNE 30,
                                                                            1998             1997
                                                                          --------         --------
<S>                                                                       <C>              <C>      
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net loss .......................................................        $(24,929)        $(29,910)
  Adjustments to reconcile net loss to net
    cash used in operating activities-
      Depreciation and amortization ..............................           4,622            3,819
       Provision for Overall Wireless ............................              --            3,611
      Increase in accounts receivable,
         prepaid expenses and other current assets ...............          (1,375)          (1,362)
      Increase in inventories ....................................          (1,826)          (1,148)
      Increase(decrease) in accounts payable, accrued liabilities,
         and other liabilities ...................................           1,889           (1,338)
                                                                          --------         --------
           Net cash used in operating
             activities ..........................................         (21,619)         (26,328)
                                                                          --------         --------
CASH FLOWS FROM INVESTING ACTIVITIES:
  Purchases of property and equipment ............................          (1,384)          (9,228)
  Other ..........................................................             156           (2,034)
  Purchase of investments ........................................              --          (14,325)
  Proceeds from the sale of investments ..........................           4,240           39,966
                                                                          --------         --------
           Net cash provided by investing activities .............           3,012           14,379
                                                                          --------         --------
CASH FLOWS FROM FINANCING ACTIVITIES:
  Proceeds from issuance of common stock .........................          54,970              494
  Cash used to retire short-term debt, net .......................          (5,000)              --
  Contributions from minority interest ...........................              --            2,191
                                                                          --------         --------
           Net cash provided by financing activities .............          49,970            2,685
                                                                          --------         --------
NET INCREASE (DECREASE) IN CASH AND
   EQUIVALENTS ...................................................          31,363           (9,264)
CASH AND EQUIVALENTS, BEGINNING OF PERIOD ........................           9,784           15,246
                                                                          --------         --------
CASH AND EQUIVALENTS, END OF PERIOD ..............................        $ 41,147         $  5,982
                                                                          ========         ========
</TABLE>



         The accompanying notes are an integral part of these condensed
                            consolidated statements.



5
<PAGE>   6



                         METRICOM, INC. AND SUBSIDIARIES
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS


NOTE 1.  BASIS OF PRESENTATION

         The condensed consolidated financial statements of Metricom, Inc. (the
"Company") presented in this Form 10-Q are unaudited. In the opinion of
management, the accompanying condensed consolidated financial statements reflect
all adjustments (which include only normal recurring adjustments) which are
necessary for a fair presentation of operations for the three and six month
periods ended June 30, 1998 and June 30, 1997. Certain information and footnote
disclosures normally included in financial statements prepared in accordance
with generally accepted accounting principles have been condensed or omitted
pursuant to the rules and regulations of the Securities and Exchange Commission.
These condensed consolidated financial statements should be read in conjunction
with the audited consolidated financial statements and the notes thereto
included in the Company's Annual Report on Form 10-K, as amended, for the year
ended December 31, 1997, as filed with the Securities and Exchange Commission.

         Certain amounts have been restated from the previously reported
balances to conform to the 1998 presentation. The preparation of financial
statements in conformity with generally accepted accounting principles requires
management to make estimates and assumptions that affect the reported amounts of
assets and liabilities and disclosures of contingent assets and liabilities at
the date of the financial statements and the reported amounts of revenues and
expenses during the reporting period. Actual results could differ from those
estimates. The results of operations for the three- and six-month periods ended
June 30, 1998 and June 30, 1997 are not necessarily indicative of the results
expected for the full fiscal year or for any other fiscal period.

NOTE 2.  INVENTORIES

         Inventories are stated at the lower of cost (first-in, first-out) or
market and include purchased parts, labor and manufacturing overhead.
Inventories consisted of the following (in thousands):

<TABLE>
<CAPTION>

                                                   JUNE 30,            DECEMBER 31,
                                                     1998                  1997
                                                    ------                ------
<S>                                                 <C>                   <C>   
Raw materials                                       $2,852                $1,660
Work-in-progress                                        --                    28
Finished goods                                       1,985                 1,323
                                                    ------                ------
  Total                                             $4,837                $3,011
                                                    ======                ======
</TABLE>




6
<PAGE>   7

NOTE 3.  COMPREHENSIVE INCOME

         The Company adopted Statement of Financial Accounting Standard No. 130
"Reporting Comprehensive Income" effective for fiscal years beginning after
December 15, 1997 and has restated information for all prior periods reported
below to conform to this standard.

<TABLE>
<CAPTION>

(In thousands)                                         Three Months Ended                 Six Months Ended
                                                              June 30,                        June 30,
                                                      1998             1997              1998             1997
                                                     -------          ------            ------           -----
<S>                                                 <C>              <C>              <C>              <C>      
NET LOSS............................................$(13,221)        $(15,951)        $(24,929)        $(29,910)

OTHER COMPREHENSIVE INCOME
  Unrealized holding gains
  on available-for-sale-securities .................       4               50                4               17
                                                    --------         --------         --------         --------

COMPREHENSIVE INCOME................................$(13,217)        $(15,901)        $(24,925)        $(29,893)
                                                    ========         ========         ========         ========
</TABLE>

NOTE 4.  BASIC AND DILUTED NET LOSS PER SHARE

         Basic and diluted net loss per share has been computed using the
weighted average number of shares of common stock outstanding. Potential common
equivalent shares from options and warrants to purchase common stock and from
conversion of the convertible subordinated notes have been excluded from the
calculation of diluted net loss per share as their effect would be
anti-dilutive.

NOTE 5.  VULCAN TRANSACTION

         On January 30, 1998, the stockholders of the Company approved the sale
of 4,650,000 shares of Common Stock to Vulcan Ventures Incorporated ("Vulcan")
at a per share price of $12.00. Upon closing of the transaction, Vulcan's
ownership interest in the Company was increased to approximately 49.5% of the
outstanding shares of Common Stock. The net proceeds from the transaction were
$53.7 million.

NOTE 6.  OVERALL WIRELESS

         In February 1996, the Company purchased an option to acquire Overall
Wireless Communications Corporation ("Overall Wireless"), a company that holds a
nationwide, wireless communications license in the 220 to 222 MHz frequency
band. The Company paid $700,000 for the option and agreed to loan Overall
Wireless up to $2.0 million for the construction of a system utilizing the
license, of which approximately $1.9 million had been loaned as of December 31,
1997. In January 1997, the Company paid $500,000 to extend the option from
January 1997 to July 1997. The option was subsequently extended to December 31,
2000 for no additional cash consideration. In June 1997, the Company recorded a
charge of $3.6 million to fully reserve its investment in Overall Wireless due
to uncertainties regarding its realization. In January 1998, 

7
<PAGE>   8

Overall Wireless canceled the option and the Company paid a termination fee of
$1.9 million through cancellation of the indebtedness of Overall Wireless.

NOTE 7.  NEW ACCOUNTING STANDARD

         In June 1997, the FASB issued SFAS No. 131, "Disclosures about Segments
of an Enterprise and Related Information" ("SFAS No. 131"), which established
standards for the way public business enterprises report information about
operating segments in annual financial statements and requires that those
enterprises report selected information about operating segments in interim
financial reports to shareholders. SFAS No. 131 also establishes standards for
related disclosures about products and services, geographic areas and major
customers. SFAS No. 131 is effective for annual reports on fiscal years
beginning after December 15, 1997, although earlier application is encouraged.
The Company believes the pronouncement will not have a material effect on its
financial statements.

         In June 1998, the Financial Accounting Standards Board issued SFAS No.
133 "Accounting for Derivative Instruments and Hedging Activities" which
establishes accounting and reporting standards for derivative instruments and
hedging activities. The Company does not expect the adoption of SFAS No. 133,
required beginning January 2000, to have a material effect on its consolidated
financial statements.



8
<PAGE>   9



ITEM 2.           MANAGEMENT'S DISCUSSION AND ANALYSIS OF
               FINANCIAL CONDITION AND RESULTS OF OPERATIONS


OVERVIEW

         Except for historical information contained herein, this Management's
Discussion and Analysis of Financial Condition and Results of Operations
contains forward-looking statements that involve risks and uncertainties. The
Company's actual results could differ materially from those discussed here.
Factors that could cause or contribute to such differences include, but are not
limited to, the completion of development of the Company's new high-speed
network, uncertainty of market acceptance of the Company's products and
services, availability of sufficient financial, management, technical and
marketing resources, performance and availability of the Company's radios and
modems, the ability of the Company to lease or acquire sites for the location of
its network infrastructure, the ability of the Company to enter into
partnerships to deploy networks and those factors discussed in the section
entitled "Risk Factors" and elsewhere in the Company's Form 10-K, as amended,
for the year ended December 31, 1997, as well as those elsewhere in this
Form 10-Q.

RESULTS OF OPERATIONS

Revenues

         Revenues consist of service and product revenues. Service revenues are
derived from the subscriber fees and modem rentals for Ricochet and fees for
UtiliNet(R) customer support and are recognized ratably over the service period.
Product revenues are derived from the sale of UtiliNet products and Ricochet
modems and are recognized upon shipment.

         Total revenues decreased to $4.4 million for the second quarter of 1998
and increased to $8.0 million for the first six months of 1998 from $4.7 million
in the second quarter of 1997 and $6.5 million for the first six months of 1997.
Service revenues increased to $2.3 million for the second quarter of 1998 and
increased to $4.3 million for the first six months of 1998 from $2.2 million in
the second quarter of 1997 and $3.4 million for the first six months of 1997.
The increase in service revenues is primarily due to increased subscriber fees
resulting from a larger Ricochet subscriber base. Product revenues decreased to
$2.1 million for the second quarter of 1998 and increased to $3.7 million for
the first six months of 1998 from $2.5 million in the second quarter of 1997 and
$3.2 million for the first six months of 1997. The fluctuations in product
revenues in the second quarter and first six months of 1998 compared with the
respective periods of 1997 was primarily due to differences in the timing of
shipments of UtiliNet products.


9
<PAGE>   10


Cost of Revenues

         Cost of service revenues consist primarily of costs incurred to deploy
and operate Ricochet networks, the cost to obtain site agreements for the
Company's network infrastructure, the cost of providing customer support,
certain costs associated with manufacturing the Company's network components and
depreciation of modems rented to Ricochet subscribers.

         Cost of service revenues were $7.6 million for the second quarter of
1998 and $13.7 million in the first six months of 1998 compared with $6.8
million in the second quarter of 1997 and $13.7 million in the first six months
of 1997. The increase in the second quarter of 1998 over the comparable period
in 1997 is primarily due to launching right of way initiatives in ten new
metropolitan areas. Cost of service revenues is expected to increase and exceed
service revenues for the foreseeable future as the Company continues to increase
efforts to obtain right of way agreements and deploy its high speed networks.

         Cost of product revenues remained relatively unchanged at $1.4 million
in the second quarter 1998 when compared with the same quarter in 1997. Cost of
product revenues for the six month period increased to $2.8 million in 1998 from
$1.7 million for the first six months of 1997. The increase was primarily due to
increased Ricochet modem sales. Cost of product revenues as a percentage of
product revenues increased to 68% for the second quarter of 1998 and 75% for the
first six months of 1998 compared with 56% and 53% for the respective periods of
1997. The increase was primarily due to a higher proportion of product revenues
thus far in 1998 derived from the sale of lower margin Ricochet modems versus
Utilinet products.

Research and Development

         Research and development expenses increased to $3.7 million for the
second quarter of 1998 and $6.8 million for the first six months of 1998 from
$2.9 million for the second quarter of 1997 and $5.9 million for the first six
months of 1997. Research and development activities include the development of a
high-speed network and subscriber device and enhancements to the technology
employed by the Company's current networks. The Company plans to continue the
high level of investment in research and development in the foreseeable future.

Selling, General and Administrative

         Selling, general and administrative expenses decreased to $4.6 million
for the second quarter of 1998 and $8.9 million for the first six months of 1998
from $5.4 million for the second quarter of 1997 and $10.8 million in the first
6 months of 1997. In the second quarter of 1998, selling expenses decreased
approximately $600,000 and general and administrative expenses decreased
approximately $200,000 compared with the second quarter of 1997. The decrease in
selling expenses is primarily attributable to a lower level of advertising
activity. The decline in general and administrative expenses primarily resulted
from decreased legal and 



10

<PAGE>   11
professional fees associated with regulatory matters in 1998. Selling, general
and administrative expenses are expected to increase for the foreseeable future.

Interest Income and Expense

         Interest expense decreased to $1.0 million in the second quarter of
1998 and $2.0 million for the first six months of 1998 from $1.2 million in the
second quarter of 1997 and $2.1 million in the first six months of 1997.
Interest expense in the second quarter of 1997 included a one-time charge for
the interest paid against short-term borrowings incurred to participate in the
FCC auction in April 1997. Interest income increased to $671,000 for the second
quarter of 1998 from $549,000 in the second quarter of 1997 primarily due to a
higher average balance of cash, cash equivalents and short-term investments in
the second quarter of 1998.

LIQUIDITY AND CAPITAL RESOURCES

         As of June 30, 1998, the Company had cash and cash equivalents and
short-term and long-term investments of $41.3 million and working capital of
$40.2 million. The Company's accounts receivable increased to $2.5 million as of
June 30, 1998 from $2.3 million as of December 31, 1997 due primarily to an
increase in the Ricochet subscriber base. The Company's inventories increased to
$4.8 million as of June 30, 1998 from $3.0 million as of December 31, 1997 due
primarily to an increase in components to be used in the manufacture of a new
high speed network. The Company believes that both accounts receivable and
inventories will increase in the future in order to support the
commercialization of its networks.

         Since inception, the Company has devoted significant resources to the
development, deployment and commercialization of its wireless network products
and services. As a result, as of June 30, 1998, the Company had incurred $174.2
million of cumulative net losses. The Company's operations have required
substantial capital investments for the purchase of network equipment, modems
and computer and office equipment. Capital expenditures were $9.2 million and
$1.4 million in the first six months of 1997 and 1998, respectively. The Company
expects that it will continue to have substantial capital requirements in
connection with the development and deployment of its networks and efforts to
attract network subscribers. The Company also expects that, to the extent its
subscriber base grows, increasingly significant capital expenditures will be
required to procure modems.

         The Company has financed its operations and capital expenditures
primarily through the public and private sale of equity and convertible debt
securities. Since inception, the Company has sold equity and convertible debt
securities creating net proceeds to the Company of approximately $217.0 million.
These sales have included (i) private placements of preferred stock with net
proceeds to the Company of approximately $18.9 million, of which $3.0 million
was repurchased and the balance converted to Common Stock at the time of the
Company's initial public offering in 1992, (ii) an initial public offering of
Common Stock with net proceeds to the Company of approximately $8.8 million in
1992, (iii) private placements of Common Stock with net proceeds to the Company
of approximately $18.6 million in 1993, (iv) public and private placements of
Common Stock with net proceeds to the Company of approximately $75.2 million in
1994, (v) a private placement of 8% Convertible Subordinated Notes due 2003 with
net proceeds to the Company of approximately $43.4 million in 1996 and (vi) a
private placement of Common Stock with Vulcan with net proceeds to the Company
of approximately $53.7 million in 1998.

         The Company believes that the Company's existing cash and investments,
interest income from investments and contributions received from strategic
partners will be adequate to satisfy its capital expenditure, operating loss and
working capital requirements through 1998. The Company will need to raise
additional funds to complete the deployment and commercialization of its current
and future networks. There can be no assurance that additional funds will be
available on commercially reasonable terms or at all. If such funding is not
available, the Company will be forced to slow technology development and network
deployment and implement additional cost-reduction measures.


11
<PAGE>   12
         The Company is in the process of identifying anticipated costs,
problems and uncertainties associated with making the Company's internal-use
software applications Year 2000 compliant. In general, the Company expects to
resolve the Year 2000 issues through planned replacement or upgrades of its
third party software applications including updating its financial management
system to Oracle 10.7. Although management does not expect Year 2000 issues to
have a material impact on its business or future results of operations, there
can be no assurance that there will not be interruptions of operations or other
limitations of system functionality or that the Company will not incur
significant costs to avoid such interruptions or limitations.

Item 4:     SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

     a)     The Annual Meeting of Stockholders of Metricom, Inc was held on June
            26, 1998.

     b)     Robert P. Dilworth, Ralph Derrickson and Timothy A. Dreisbach were
            elected to the Board of Directors to hold office until the 2001
            Annual Meeting of Stockholders and until their successors are
            elected.

     c)     The following persons are persons whose terms of office as Directors
            of the Company continued after the meeting:

<TABLE>
<CAPTION>
            Director                                    Term Expires
            --------                                    ------------
            <S>                                         <C> 
            David E. Liddle                                 2000
            William D. Savoy                                2000
            Robert S. Cline                                 1999
            Justin L. Jaschke                               1999
</TABLE>

     d)     The matters voted upon at the meeting and the voting of stockholders
            with respect thereto are as follows:

     1)     Elect Robert P. Dilworth, Ralph Derrickson and Timothy A. Dreisbach
            as Directors to hold office until the 2001 Annual Meeting of
            Stockholders and until their successors are elected:

<TABLE>
<CAPTION>
                                                        For             Withheld
                                                     ----------         --------
            <S>                                      <C>                <C>   
            Robert P. Dilworth                       11,103,097          61,235
            Ralph Derrickson                         11,111,928          52,404
            Timothy A. Dreisbach                     11,105,452          58,880
</TABLE>

     2)     Approve the Company's 1997 Equity Incentive Plan, as amended.

            For: 9,949,440          Against: 1,160,821           Abstain: 54,071

     3)     Approve the Company's 1991 Employee Stock Purchase Plan, as amended.

            For: 10,896,279         Against: 214,405             Abstain: 53,648

     4)     Approve the Company's 1993 Non-Employee Directors' Stock Option
            Plan, as amended.

            For: 10,070,961         Against: 1,025,635           Abstain: 67,736

     5)     Ratify the selection of Arthur Andersen LLP as independent auditors
            of the Company for its fiscal year ending December 31, 1998

            For: 11,076,912         Against: 44,215              Abstain: 43,205


12
<PAGE>   13
ITEM 5.  OTHER INFORMATION

Pursuant to the Company's bylaws, stockholders who wish to bring matters or
propose nominees for director at the Company's 1999 annual meeting of
stockholders must provide specified information to the Company by January 22,
1999 (unless such matters are included in the Company's proxy statement pursuant
to Rule 14a-8 under the Securities Exchange Act of 1934, as amended).
Notwithstanding the foregoing, in the event the date of the 1999 annual meeting
of stockholders is changed by more than 30 days from the date contemplated at
the time the Company's proxy statement for the 1998 annual meeting of
stockholders was sent to stockholders, stockholders who wish to bring matters or
propose nominees for director must provide such information to the Company
within a reasonable time before the proxy statement relating to the 1999 annual
meeting of stockholders is sent to stockholders.


ITEM 6:  EXHIBITS AND REPORTS ON FORM 8-K

         a. Exhibits:

            27.1   Financial Data Schedule

         b. Reports on Form 8-K:  None



13
<PAGE>   14


                                   SIGNATURES

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.


                                        METRICOM, INC.
                                        (Registrant)




                                     By: /s/ VANESSA A. WITTMAN
                                        ----------------------------------------
Date: August 12, 1998                   Vanessa A. Wittman
                                        Chief Financial Officer and Duly 
                                        Authorized Officer



14
<PAGE>   15

                                 EXHIBIT INDEX

<TABLE>
<CAPTION>


         Exhibit #       Description
         ---------       -----------

<S>                      <C>               
           27.1          Financial Data Schedule

</TABLE>