<PAGE>   1

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ----------------------
                                    FORM 10-Q

                Quarterly Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934
                  for the quarterly period ended April 29, 2000

                         Commission File Number 0-19558

                      CENTIGRAM COMMUNICATIONS CORPORATION
             (Exact name of registrant as specified in its charter)

                   Delaware                             94-2418021
           (State of incorporation)                  (I.R.S. Employer
                                                  Identification Number)

                              91 East Tasman Drive
                           San Jose, California 95134
                    (Address of principal executive offices)

       Registrant's telephone number, including area code: (408) 944-0250

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 outstanding shares of the Registrant's Common Stock as of May 26,
2000 was 7,051,000.


<PAGE>   2

PART I - FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

Centigram Communications Corporation
Condensed Consolidated Balance Sheets

<TABLE>
<CAPTION>
(In thousands, except share and per share data)                              April 29, 2000    October 30, 1999
---------------------------------------------------------------------------------------------------------------
                                                                              (Unaudited)           (Note)
<S>                                                                           <C>                  <C>
ASSETS
Current assets:
    Cash and cash equivalents                                                   $ 15,100           $ 10,563
    Short-term investments                                                        41,303             34,135
    Trade receivables, net                                                        14,033             16,829
    Inventories                                                                    2,379              2,342
    Other current assets                                                           1,184              1,378
                                                                                --------           --------
       Total current assets                                                       73,999             65,247
Property and equipment, net                                                        4,536              4,062
Intangible assets, net                                                             4,695              5,233
Deposits and other assets                                                          4,171              4,212
                                                                                --------           --------
                                                                                $ 87,401           $ 78,754
                                                                                ========           ========
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
    Accounts payable                                                            $  4,218           $  3,866
    Accrued compensation                                                           4,209              4,229
    Deferred income                                                                2,312              3,385
    Accrued expenses and other liabilities                                         5,994              6,500
    Treasury stock settlement payable                                             12,095                 --
    Warranty and retrofit reserves                                                 1,930              1,945
                                                                                --------           --------
       Total current liabilities                                                  30,758             19,925
Commitments and contingencies
Stockholders' equity
    Preferred stock, $.001 par value, 1,000,000 authorized;
       none outstanding                                                               --                 --
    Common stock, $.001 par value, 25,000,000 authorized;
       7,171,000 outstanding and capital in excess of par value                   90,064             90,235
    Treasury stock, 130,000 and 1,206,000 shares,                                (11,020)           (12,915)
       at cost
    Accumulated deficit                                                          (27,808)           (18,451)
    Accumulated other comprehensive income                                         5,407                (40)
                                                                                --------           --------
       Total stockholders' equity                                                 56,643             58,829
                                                                                --------           --------
                                                                                $ 87,401           $ 78,754
                                                                                ========           ========
</TABLE>

Note: The balance sheet at October 30, 1999 has been derived from the audited
financial statements at that date but does not include all of the information
and footnotes required by generally accepted accounting principles for complete
financial statements. See accompanying notes.


                                       2
<PAGE>   3

Centigram Communications Corporation
Condensed Consolidated Statements of Operations (Unaudited)

<TABLE>
<CAPTION>
                                                                Quarter Ended               Six Months Ended
                                                       -----------------------------  ----------------------------
(In thousands, except per share data)                  April 29, 2000    May 1, 1999  April 29, 2000   May 1, 1999
------------------------------------------------------------------------------------------------------------------

<S>                                                    <C>               <C>          <C>              <C>
Net revenue                                                $ 20,327       $ 20,835       $ 39,341       $ 41,068
Cost and expenses:
  Costs of goods sold                                         6,510          8,768         12,453         17,702
  Research and development                                    3,772          4,189          7,392          8,342
  Selling, general and administrative                         8,918          8,630         17,584         16,950
  Non-recurring charges                                      12,095             --         12,095             --
                                                           --------       --------       --------       --------
       Total costs and expenses                              31,295         21,587         49,524         42,994
                                                           ========       ========       ========       ========
Operating loss                                              (10,968)          (752)       (10,183)        (1,926)
Other income and expense, net                                   818            670          1,527          1,260
                                                           --------       --------       --------       --------
Loss before income taxes                                    (10,150)           (82)        (8,656)          (666)
Provision for income taxes                                      399            110            701            205
                                                           --------       --------       --------       --------
Net loss                                                   $(10,549)      $   (192)      $ (9,357)      $   (871)
                                                           ========       ========       ========       ========

Basic and diluted loss per share                           $  (1.50)      $  (0.03)      $  (1.34)      $  (0.13)
                                                           ========       ========       ========       ========

Shares used for basic and diluted loss per share              7,020          6,332          6,965          6,452
                                                           ========       ========       ========       ========
</TABLE>

See accompanying notes.


                                       3
<PAGE>   4

Centigram Communications Corporation
Condensed Consolidated Statements of Cash Flows (Unaudited)

<TABLE>
<CAPTION>
                                                                                     Six Months Ended
                                                                             -------------------------------
(In thousands)                                                               April 29, 2000      May 1, 1999
------------------------------------------------------------------------------------------------------------
<S>                                                                          <C>                 <C>
Cash and equivalents, beginning of period                                       $ 10,563           $ 23,430
                                                                                --------           --------

Cash flows from operations:
    Net loss                                                                      (9,357)              (871)
    Depreciation and amortization                                                  1,837              3,078
    Trade receivables, net                                                         2,796             (1,737)
    Inventories                                                                      (37)             2,299
    Other assets                                                                     623                294
    Accounts payable                                                                 352               (348)
    Accrued expenses and other liabilities                                        (1,614)           (10,380)
    Treasury stock settlement payable                                             12,095                 --
                                                                                --------           --------
                                                                                   6,695             (7,665)
                                                                                --------           --------
Cash flows from investing:
    Purchase of short-term investments                                           (34,390)           (40,468)
    Proceeds from sale and maturities of short-term investments                   32,786             37,347
    Purchase of property and equipment                                            (1,890)            (1,343)
                                                                                --------           --------
                                                                                  (3,494)            (4,464)
                                                                                --------           --------
Cash flows from financing:
    Proceeds from sale of common stock                                             1,868                409
    Purchase of treasury shares                                                     (144)            (5,439)
    Increase in restricted cash                                                     (388)                --
                                                                                --------           --------
                                                                                   1,336             (5,030)
                                                                                --------           --------
Net change in cash and equivalents                                                 4,537            (17,159)
                                                                                --------           --------
Cash and equivalents, end of period                                             $ 15,100           $  6,271
                                                                                ========           ========
</TABLE>
See accompanying notes.


                                       4
<PAGE>   5

Centigram Communications Corporation
Notes to Condensed Consolidated Financial Statements (Unaudited)

BASIS OF PRESENTATION

         The accompanying condensed consolidated financial statements have been
prepared by the Company without audit and reflect all adjustments (consisting of
normal recurring adjustments) which are, in the opinion of management, necessary
to reflect a fair statement of the consolidated results for the interim periods.
For further information, refer to the audited Consolidated Financial Statements
and footnotes included in the Company's Annual Report on Form 10-K for the
fiscal year ended October 30, 1999. The results of operations for the three and
six month periods ended April 29, 2000 may not necessarily be indicative of the
results for the fiscal year ending October 28, 2000 or any future period.

INVENTORIES

         Inventories consisted of:

<TABLE>
<CAPTION>
         (In thousands)                                   April 29, 2000   October 30, 1999
         ----------------------------------------------------------------------------------
         <S>                                              <C>              <C>
         Raw materials                                        $  457            $  505
         Work-in-process                                       1,302             1,134
         Finished goods                                          620               703
                                                              ------            ------
                                                              $2,379            $2,342
                                                              ======            ======
</TABLE>

LOSS PER SHARE

         Basic and diluted earnings per share are computed using the weighted
average number of common shares outstanding during the periods. In computing
diluted earnings per share in periods with income, the dilutive effect of
options are also included in the per share computation. Options to purchase
common stock were outstanding during the quarter and six months ended April 29,
2000 and May 1, 2000, but were not included in the computation of diluted net
income per share because the options' exercise price was greater than the
average market price of the common shares and, therefore, the effect would be
antidilutive. The per share amounts for the second quarter and the year-to-date
calculation for the first six months of fiscal year 2000 reflect as outstanding
the 900,000 treasury shares deposited by the Company with Credit Bancorp, Ltd.
that have not been returned to the Company. See Legal Proceedings (Part II, Item
1). The details of these computations are as follows:

<TABLE>
<CAPTION>
                                                        Quarter Ended                Six Months Ended
                                                ----------------------------  ----------------------------
(In thousands, except per share data)           April 29, 2000   May 1, 1999  April 29, 2000   May 1, 1999
----------------------------------------------------------------------------------------------------------
<S>                                             <C>              <C>          <C>              <C>
Net loss                                           $(10,549)      $   (192)      $ (9,357)      $   (871)
                                                   ========       ========       ========       ========

Weighted average shares outstanding                   7,020          6,332          6,965          6,452
Effect of dilutive securities:
    Shares issued upon exercise of
    dilutive outstanding stock options                   --             --             --             --
                                                   --------       --------       --------       --------
Adjusted weighted average shares                      7,020          6,332          6,965          6,452
                                                   ========       ========       ========       ========

Basic loss per share                               $  (1.50)      $  (0.03)      $  (1.34)      $  (0.13)
                                                   ========       ========       ========       ========
Diluted loss per share                             $  (1.50)      $  (0.03)      $  (1.34)      $  (0.13)
                                                   ========       ========       ========       ========
</TABLE>


                                       5
<PAGE>   6

COMPREHENSIVE INCOME (LOSS)

         In the first quarter of fiscal 1999, the Company adopted the Statement
on Financial Accounting Standards No. 130 (SFAS 130), "Reporting Comprehensive
Income." SFAS 130 establishes new rules for the reporting and display of
comprehensive income and its components; however adoption of this Statement had
no impact on the Company's net income or shareholders' equity. SFAS 130 requires
unrealized gains or losses on the Company's available-for-sale securities and
foreign currency translation adjustments to be included in other comprehensive
income rather than as a separate component of shareholders' equity.

         The following are the components of comprehensive income (loss), net of
related tax:

<TABLE>
<CAPTION>
                                                            Quarter Ended                Six Months Ended
                                                    ---------------------------   ---------------------------
         (In thousands)                             April 29, 2000  May 1, 1999   April 29, 2000  May 1, 1999
         ----------------------------------------------------------------------------------------------------
         <S>                                        <C>             <C>           <C>             <C>
         Net loss                                      $(10,549)      $   (192)      $ (9,357)      $   (871)
         Unrealized gain (loss) on
            Investments                                   1,181            (30)         5,564            (93)
         Foreign currency translation
            Adjustment                                      (83)           (43)          (117)           (66)
                                                       --------       --------       --------       --------
                                                       $ (9,451)      $   (265)      $ (3,910)      $ (1,030)
                                                       ========       ========       ========       ========
</TABLE>

         The following are the components of accumulated other comprehensive
income:

<TABLE>
<CAPTION>
         (In thousands)                                           April 29, 2000    October 30, 1999
         -------------------------------------------------------------------------------------------
         <S>                                                      <C>               <C>
         Unrealized gain on investments                              $  5,645           $     81
         Foreign currency translation adjustment                         (238)              (121)
                                                                     --------           --------
                                                                     $  5,407           $    (40)
                                                                     ========           ========
</TABLE>

NON-RECURRING CHARGES

         In June 2000, the Company settled its dispute with Credit Bancorp over
the return of the Company's treasury shares for a total cash payment of
approximately $12.1 million payable upon the delivery of these shares to the
Company. This amount has been accrued as a payable as of the second quarter
ended April 29, 2000. See Subsequent Events note for further details.

SUBSEQUENT EVENTS

         Amendment of Patent License. On May 25, 2000, the Company and Lucent
Technologies, Inc. ("Lucent") amended in certain respects the Patent License
Agreement dated October 1, 1998 and extended the term of the agreement for an
additional five years. The Company agreed to pay Lucent the sum of $6.0 million
in consideration for the modifications and the extension. This amount will be
amortized over the remaining term of the agreement, as extended.

         Agreement with Credit Bancorp Receiver. On June 7, 2000, the Company
and Carl H. Loewenson, Jr., as the Court-Appointed Receiver for Credit Bancorp,
Ltd., reached an agreement providing for the return of the 900,000 treasury
shares deposited by the Company with Credit Bancorp. The agreement provides for
the receiver to use reasonable commercial efforts to return the Company's
treasury shares, which are held in accounts in the name of Credit Bancorp, in
exchange for a cash payment of approximately $12.1 million, payable upon
delivery of the shares. The Company has recorded a charge to operations in that
amount in the quarter ended April 29, 2000. The Company also agreed to release
Credit Bancorp and the receiver from all claims that the Company may have
against Credit Bancorp relating to the deposit of the treasury shares. The
receiver, on behalf of Credit Bancorp, agreed to release the Company from all
claims for contribution or liability to the receivership estate or claim to
ownership of the Company's deposited treasury shares. The court supervising the
Credit Bancorp receivership approved the agreement on June 14, 2000.


                                       6
<PAGE>   7

         Acquisition by ADC Telecommunications, Inc. On June 9, 2000, the
Company and ADC Telecommunications, Inc. ("ADC") entered into an Agreement and
Plan of Merger providing for the acquisition of the Company by ADC. ADC will pay
cash for all Company shares outstanding as of the closing and will assume
Company stock options outstanding as of the closing for a total purchase price
of approximately $200 million. Because of the fixed purchase price, the per
share amount to be received by the Company's stockholders will be determined as
of the closing based on the number of shares outstanding and shares subject to
options outstanding on that date.

         Based upon the number of shares outstanding and shares subject to
options outstanding on May 26, 2000, the purchase price will consist of
approximately $163 million in cash to the Company's stockholders and
approximately $36 million in ADC stock paid through the conversion of the
Company's stock options into ADC stock options. A portion of the cash
consideration will be placed in escrow if at the closing the Company has not
fully recovered its treasury shares from the receiver for Credit Bancorp or if
the court's order approving the Company's agreement with the receiver for the
return of the treasury shares has been appealed or the period in which an appeal
may be taken has not expired. If these matters relating to the treasury shares
have been resolved prior to the closing, the Company's stockholders would
receive, based upon the number of shares outstanding and shares subject to
options outstanding on May 26, 2000, approximately $26.38 per share of common
stock.

         If the treasury share matters have not been resolved prior to closing,
the Company's stockholders would receive, based upon the number of shares
outstanding and shares subject to options outstanding on May 26, 2000,
approximately $23.84 per share of common stock and approximately $21.5 million
($23.84 per share multiplied by 900,000 shares) in cash will be placed in escrow
until the treasury shares are fully recovered or any appeal has been finally
resolved or the appeal period has expired. If ADC or the Company incurs any
additional liability or expense relating to the treasury shares after the
closing, the liability and expense will be paid from the escrowed funds. The
amount remaining in escrow after the resolution of all treasury share issues
will be paid to the Company's former stockholders and the ADC options received
upon conversion of the Company's stock options will be appropriately adjusted.


                                       7
<PAGE>   8

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

         The following discussion contains forward-looking statements regarding
future events or the future financial performance of Centigram that involve
risks and uncertainties. These statements include but are not limited to
statements related to changes in Centigram's research and development and
selling, general and administrative expenses, Centigram's effective tax rate,
Centigram's expenditures for capital equipment, and the sufficiency of
Centigram's cash reserves. Actual results could differ materially from those
anticipated in these forward-looking statements as a result of certain factors,
including those set forth in this Management's Discussion and Analysis of
Financial Condition and Results of Operations under "Certain Trends and
Uncertainties," and elsewhere herein.

         Centigram designs, manufactures and markets unified communications,
messaging, Internet- and WAP-enabled call management services to wireless,
wireline and Internet service providers. Centigram's applications operate on
common hardware and software platforms based on industry-standard hardware and
software, which is the Company's implementation of its Modular Expandable System
Architecture (MESA). Centigram's system architecture enables a user generally to
expand the capacity of a system in cost-effective increments from the Company's
smallest to its largest system configuration. Centigram's systems can be
integrated with wireline and wireless switches, paging systems and IP gateways.
Such systems are used for switching telephone calls and integrating voice and
data messaging in a variety of service provider environments. In addition,
Centigram systems located at different sites can be linked together in a digital
network.

RESULTS OF OPERATIONS

         Net revenue for the second quarter of fiscal 2000 was $20.3 million,
which was 2% lower than net revenue for the corresponding quarter of fiscal
1999. Net revenue for the first six months of fiscal 2000 was $39.3 million,
which was 4% lower than net revenue for the comparable period of fiscal 1999.
The change in net revenue for the second quarter and six months of 2000, as
compared to similar periods in 1999, reflects lower sales of upgrades and
expansion products, prepaid system sales, and custom developed software. This
decrease was offset in part by higher sales of large system products. Sales to
international customers were 35% and 39% of revenues for the second quarter and
six months of 2000, respectively, as compared to 43% and 41% in the similar
period of 1999.

         Gross margin was 68.0% and 57.9% of net revenue in the second quarters
and 68.3% and 56.9% for the six months of 2000 and 1999, respectively. This
10.1% and 11.4% increases from the prior year's second quarter and six months
reflect improved margins in large system products with improved mix
configurations, which favorably improves gross margins and higher prices for
these products. See "Certain Trends and Uncertainties."

         Research and development ("R&D") expenses were $3.8 million and $7.4
million in the second quarter and six months of 2000, decreasing 10% and 11%
from the corresponding periods of 1999. R&D expenses as a percentage of net
revenue was 19% and 20% for the second quarter and for the six months of 2000
and 1999, respectively. This year over year decrease reflects reduced prototype
expense and lower depreciation expenses. The Company believes that ongoing
development of new products and features is required to maintain and enhance its
competitive position and accordingly, the Company expects to continue to invest
in R&D.

         Selling, general and administrative ("SG&A") expenses were $8.9 million
and $17.6 million for the second quarter and six months of 2000, increasing 3%
and 4% from the corresponding period of 1999. This change reflects increased
salaries and related headcount expenses in sales and marketing. SG&A expenses as
a percentage of net revenue were 44% and 41% for the second quarter and 45% and
41% for the six months of 2000 and 1999, respectively.

         Non-recurring charges were $12.1 million and zero for the three and six
month periods of 2000 and 1999, respectively. These non-recurring charges
consisted of amounts to settle the litigation dispute with Credit Bancorp over
the return of the Company's treasury shares. See Legal Proceedings (Part II,
Item 1).

         Other income and expense, net, was $0.8 million and $0.7 million for
the second quarter and $1.5 million and $1.3 million for the six months of 2000
and 1999, respectively. Other income and expense, net, is composed primarily of
interest income on investments and foreign currency transaction gains and
losses. The increase in year over year balances was primarily due to increases
in interest income on investments.

         For the second quarter and six months of fiscal 2000, the Company
recorded a provision for income taxes. The rate is lower than the statutory rate
due to recognition of previously unrecognized benefits of net operating


                                       8
<PAGE>   9

loss carry-forwards. The Company recorded a provision for income taxes for the
second quarter and six months of fiscal 2000 and 1999 for anticipated foreign
income tax liabilities. No income tax benefits were recorded for the losses
incurred in fiscal years 2000 and 1999 because realization of the deferred tax
asset arising as a result of the losses sustained is dependent upon future
taxable income, the amount and timing of which are uncertain. Accordingly, a
valuation allowance has been established to fully offset the deferred tax asset
other than that which represents potentially refundable taxes.

         Net loss for the second quarter and six months of fiscal year 2000 was
$10.5 million and $9.4 million, or $(1.50) and $(1.34) per share, compared with
a net loss of $0.2 million and $0.9 million, or $(0.03) and $(0.13) per share,
for the corresponding periods of fiscal year 1999. The net loss per share
amounts for second quarter and the year-to-date calculation for the first six
months of fiscal year 2000 reflect as outstanding the 900,000 shares deposited
by the Company with Credit Bancorp, Ltd. that have not been returned to the
Company. See Legal Proceedings (Part II, Item 1) for a description of the Credit
Bancorp matter.

LIQUIDITY AND CAPITAL RESOURCES

         Cash and cash equivalents and short-term investments at April 29, 2000
were $56.4 million, increasing $11.7 million from the year-end balance of $44.7
million.

         For the first six months ended April 29, 2000 the net cash generated
from operating activities was $6.7 million. Short-term investments increased
approximately $5.6 million from year-end because of the mark to market
adjustment of the Company's common stock and warrants in InfoInterActive Inc.
("IIA") as of April 29, 2000. Trade receivables decreased $2.8 million from the
year-end balance and days sales outstanding (computed using quarterly revenues)
were 62 days at the end of the second quarter as compared to 72 days at end of
fiscal 1999. Inventory levels were $2.4 million at the end of the second
quarter, unchanged from the 1999 fiscal year end. The Company expects
investments in receivables and inventories will continue to represent a
significant portion of working capital. In June 2000, the Company settled its
dispute with Credit Bancorp over the return of the Company's treasury shares for
a total cash payment of approximately $12.1 million payable upon the delivery of
these shares to the Company. This amount has been accrued as a payable as of the
second quarter ended April 29, 2000.

         During the six months ended April 29, 2000, the Company made capital
expenditures of approximately $1.9 million. These expenditures consisted
primarily of purchases of computer equipment, software, and engineering lab
equipment. The Company currently expects to spend approximately $3.0 to $4.0
million for capital equipment during fiscal 2000, although actual expenditures
may differ from this forecast. In addition, the Company's Board of Directors has
authorized a stock repurchase program whereby up to 2,500,000 shares of its
Common Stock may be repurchased in the open market from time-to-time. The
Company has purchased approximately 1,676,000 shares under this program at a
total cost of approximately $18.7 million.

         The Company's principal sources of liquidity as of April 29, 2000
consisted of $56.4 million of cash and cash equivalents and short-term
investments. The Company presently believes, notwithstanding its accumulated
deficit, that its existing cash and short-term investments will be sufficient to
support the Company's working capital, capital equipment purchase requirements,
and stock repurchase program at least for the next twelve months.

CERTAIN TRENDS AND UNCERTAINTIES

         The Company has in the past experienced and will likely in the future
experience substantial fluctuations in quarterly operating results. The Company
generally has no long-term order commitments from its customers, and a
significant portion of bookings and shipments in any quarter have historically
occurred near the end of the quarter. Accordingly, the Company has historically
operated with very little backlog, and net revenue has been difficult to
predict. In addition, the portion of backlog shippable in the next quarter
varies over time. As a result, revenue in future quarters will depend largely on
the level of orders received during such quarters.

         If new order bookings do not meet expected levels, or if the Company
experiences delays in shipments at the end of a quarter, operating results will
be adversely affected, and these developments may not become apparent to the
Company until near or at the end of a quarter. Net revenue can also be affected
by product sales mix, distribution mix, the size and timing of customer orders
and shipments, customer returns and reserves provided therefore, competitive
pricing pressures, the effectiveness of key distributors and the Company's sales
force in


                                       9
<PAGE>   10

selling the Company's products, changes in distributor inventory levels, the
ability of the Company's joint marketing partners to ship products during the
quarter, the timing of new product introductions by the Company and its
competitors, regulatory approvals, and the availability of components for the
Company's products, each of which is difficult to predict accurately. Each of
such factors has in the past affected the Company's revenue. The Company has in
the past experienced higher than usual headcount turnover, which has had an
adverse effect on the Company's booking levels. There can be no assurance that
such turnover will not continue in future periods. Any failure by the Company to
attract, retain and train additional sales and other personnel could have a
material adverse effect on the Company's business and results of operations.

         A significant portion of the Company's net revenue is attributable to a
limited number of customers. The Company's top five customers accounted for
approximately 44% and 55% of the Company's net revenue in the first six months
of fiscal 2000 and 1999, respectively, although the Company's five largest
customers were not the same in the two periods. Any material reduction in orders
from one or more of such customers or the cancellation or deferral of any
significant portion of backlog could have an adverse effect on net revenue and
operating results. Such concentration of sales typically results in a
corresponding concentration of accounts receivable. Although the Company has
established reserves for uncollectible accounts, the inability of any large
customer to pay the Company could have a material adverse impact on the
Company's financial position, results of operations and cash flows.

         Approximately 35% and 39% of the Company's sales in the second quarter
and six months ended April 29, 2000 consisted of sales outside of the United
States. The Company's international sales are subject to a number of additional
risks generally associated with international sales, including the effect on
demand for the Company's products in international markets as the results of any
strengthening or weakening of the U.S. dollar, the effect of currency
fluctuations on consolidated multinational financial results, state imposed
restrictions on the repatriation of funds, import and export duties and
restrictions, the need to modify products for local markets, and the logical
difficulties of managing multinational operations. In particular, the Company's
sales in Asia and Latin American have been adversely affected in recent years by
financial difficulties in these regions and sales levels may be so adversely
affected in the future.

         The Company's gross margin can be affected by a number of factors,
including changes in product configuration and mix including the volume of OEM
products, distribution channel and customer mix, cost and availability of parts
and components, royalty obligations to suppliers of licensed software,
provisions for warranty, retrofits, and excess and obsolete inventory, customer
returns, and competitive pressures on pricing. The Company has experienced
increasing competitive pricing pressure in its markets and expects this pricing
pressure to continue. Further, distributors purchase products at discounts, and
the Company's margins can therefore vary depending upon the mix of distributor
and direct end user sales in any particular fiscal period. While the Company
anticipates that its sales mix will continue to fluctuate in future periods, the
Company anticipates selling an increasing percentage of sales through direct
sales rather than through distribution.

         The Company's future success will depend in part upon the ability of
the Company to continue to introduce new features and products as the Company's
markets evolve, new technologies become available, and customers demand
additional functionality. The Company's competitors continue to add
functionality to their products, and any failure by the Company to introduce in
a timely manner new products and features that meet customer requirements would
adversely affect the Company's operating results and cash flows. The Company's
ability to develop such new features and products depends in large measure on
its ability to hire and retain qualified technical talent and outside
contractors in highly competitive markets for such services. There can be no
assurance that the Company's product development efforts will be successful, or
that it will be able to introduce new products in a timely manner. Any material
additional delays in the introduction and market acceptance of such products
would be adverse to the Company's business. Moreover, customers' expectations of
the introduction of new products by the Company or its competitors can adversely
affect sales of current products. In addition, upon the introduction of new
products, the Company could be subject to higher customer returns with respect
to prior generations of products, which could adversely affect the Company's
financial position, operating results and cash flows.

         The Company presently uses third parties to perform printed circuit
board and subsystem assembly. In addition, although the Company has not
experienced significant problems with third-party manufacturers in the past,
there can be no assurance that such problems will not develop in the future.
Although the Company generally


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<PAGE>   11

uses standard parts and components for its products, certain microprocessors,
line cards, application cards and other semiconductor devices and other
components are available from sole sources. Other components, including power
supplies, disk drives, certain other semiconductor devices and subcontracted
line card assemblies, are presently available or acquired from a single source
or from limited sources. The Company has been notified by suppliers that certain
components will no longer be manufactured. To date, the Company has been able to
obtain adequate supplies of these components in a timely manner from existing
sources or, when necessary, from alternative sources of supply although such
alternatives have resulted in increased costs to the Company. However, the
inability to develop such alternative sources if and as required in the future,
to obtain sufficient sole or limited source components as required, or to locate
alternatives to discontinued parts would have a material adverse affect on the
Company's operating results and cash flows. In addition, the Company's products
are dependent on the QNX software operating system, a multitasking, real-time
operating system for Intel microprocessor-based computers. In future periods,
the Company's products may become increasingly dependent on software licensed
from third party suppliers. There can be no assurance such licenses will
continue to be available to the Company as needed or at commercially reasonable
prices.

         In addition, a number of other companies, including competitors of the
Company, hold patents in the same general area as the technology used by the
Company. The Company from time to time has received, and may receive in the
future, letters alleging infringement of patent rights by the Company's
products. For example, in December 1997, representatives of Lucent informed the
Company that they believed that the Company's products may infringe upon certain
patents issued to Lucent, and that Lucent was seeking compensation for any past
infringement by the Company. The Company evaluated the assertions of Lucent, and
in October 1998 settled with Lucent by signing an intellectual property
cross-licensing agreement and in November 1998 paid Lucent $9.2 million. Third
party companies alleging infringement could seek an injunction prohibiting the
Company from selling some or all of its products, which would have an immediate,
adverse impact in the Company's business, financial condition and results of
operations. There can be no assurance that the Company would prevail in any
litigation to enjoin the Company from selling its products on the basis of such
alleged infringement, or that the Company would be able to license any valid and
infringed patents on reasonable terms, or at all.

         Like many other companies, the year 2000 computer issue creates risks
for Centigram. If internal systems do not correctly recognize and process date
information beyond the year 1999, there could be an adverse impact on the
Company's operations. To address the year 2000 issues with its internal systems,
the Company has completed and tested its critical systems with the help of
outside consultants and contractors. These activities encompassed all major
categories of systems in use by the Company, including network and
communications infrastructure, manufacturing, sales, customer service, finance
and administration. As of April 29, 2000, all critical systems are considered by
the Company to be year 2000 capable. The Company has also worked with its
critical suppliers of products to determine that the suppliers' operations and
the products they provide are year 2000 capable. The Company has received
responses from its critical suppliers that they are year 2000 capable. In
addition, the Company has completed a contingency plan to address potential
problem areas with internal systems and with suppliers and other third parties.

         The Company also has a program to assess the capability of its products
to handle the year 2000. As used by Centigram, "Year 2000 Capable" means that
when used properly and in conformity with the product information provided by
Centigram, the Centigram product will accurately store, display, process,
provide, and/or receive data from, into, and between the twentieth and
twenty-first centuries, including leap year calculations, provided that all
other technology used in combination with the Centigram product properly
exchanges date data with the Centigram product. The Company believes that its
products are year 2000 capable. The Company is incurring various costs to
provide customer support and customer satisfaction services regarding year 2000
issues and it is anticipated that these expenditures will continue.

         Based on currently available information, management does not believe
that the year 2000 matters discussed above related to internal systems or
products sold to customers will have a material adverse impact on the Company's
financial condition or overall trends in results of operations. There can be no
assurance that the failure to ensure year 2000 capability by a supplier or
another third party would not have a material adverse effect on the Company.

         In April 1998 the Company entered into an Agreement for Purchase and
Sale of Assets with Mitel, Inc. and Mitel Corporation (collectively, "Mitel")
providing for the purchase by Mitel of the Company's customer


                                       11
<PAGE>   12

premises equipment ("CPE") business. Pursuant to this agreement, the Company has
agreed, until May of 2001, not to compete with Mitel in the CPE business. As a
result, the Company is unable to sell its equipment or services to certain
customers, which could adversely affect the Company's business, financial
condition and results of operations.

         In recent years, stock markets have experienced extreme price and
volume trading volatility. This volatility has had a substantial effect on the
market prices of securities of many high technology companies for reasons
frequently unrelated to the operating performance of the specific companies.
These broad markets fluctuations may adversely affect the market price of the
Company's common stock. In addition, the trading price of the Company's common
stock could be subject to wide fluctuations in response to quarter-to-quarter
variations in operating results, announcements of new products or technological
innovations by the Company or its competitors, and general conditions in the
computer and communications industries.

PART II - OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

DEPOSIT OF TREASURY STOCK WITH CREDIT BANCORP

         In August 1999 the Company entered into a credit facility with Credit
Bancorp, Ltd. Pursuant to the credit facility, the Company deposited 900,000
shares of its treasury stock with Credit Bancorp to serve as security if the
Company borrowed funds under the credit facility. Credit Bancorp agreed that the
Centigram treasury shares were to be placed in a trust account and were not to
be sold, pledged, margined or otherwise transferred. Contrary to the express
terms of the credit facility, Credit Bancorp placed Centigram treasury shares in
margin accounts and borrowed against these shares. The Company did not borrow
any funds under the Credit Bancorp credit facility.

         In November 1999 the Securities and Exchange Commission commenced a
civil action against Credit Bancorp and certain entities and individuals
affiliated with it, alleging numerous violations of the federal securities laws
relating to Credit Bancorp's "insured credit facility program." The SEC alleges
that the Credit Bancorp defendants induced customers to place restricted
securities in trust accounts with Credit Bancorp, which securities Credit
Bancorp improperly either sold or used to obtain margin loans and converted the
proceeds. The Credit Bancorp credit facility entered into by the Company is
similar to the "insured credit facility" described in the SEC complaint and the
SEC recognizes the Company as a customer in the insured credit facility program.
In December 1999 the Company terminated the Credit Bancorp credit facility and
demanded the return of the treasury shares. In connection with its action
against the Credit Bancorp defendants, the SEC subpoenaed the Company to produce
all documents relating to its Credit Bancorp credit facility. The Company
cooperated fully with the SEC.

         Upon the request of the SEC, the United States District Court for the
Southern District of New York issued a temporary restraining order against the
Credit Bancorp defendants prohibiting any further violation of the federal
securities laws. The court also froze the assets owned by, controlled by, or in
the name of the Credit Bancorp defendants, including the Centigram treasury
shares. In January 2000, the court appointed a receiver to take control of the
funds, assets and property owned by, controlled by, or in the name of Credit
Bancorp and to take any action necessary and appropriate to preserve and prevent
the dissipation of those funds, assets and properties. The receiver reported to
the Company that none of the 900,000 treasury shares had been sold by Credit
Bancorp and that all Centigram treasury shares remain in brokerage accounts in
the name of Credit Bancorp. Under the court's order, the receiver may not sell
any securities deposited by Credit Bancorp customers, including the Company's
treasury shares, without the approval of the Court after notice to all Credit
Bancorp customers.

         In the second quarter of fiscal year 2000, the Company intervened in
the SEC civil action against the Credit Bancorp defendants and requested the
court to lift the freeze order and direct the receiver to return the deposited
Centigram shares. The SEC and the receiver took the position that the Centigram
shares are the property of the receivership estate, which Centigram vigorously
disputed. The court denied Centigram's request for the return of the shares, but
granted Centigram leave to renew its motion upon a change in circumstances. The
court did not, however, rule on the merits of the ownership issue. Because of
the court's initial ruling, the Company has included, out of an abundance of
caution, the deposited shares as outstanding in the net income per share amounts
for the second quarter and the first six months of fiscal year 2000.


                                       12
<PAGE>   13

         On May 25, the SEC filed with the court a Plan of Partial Distribution.
If approved by the court, the Plan would authorize the receiver to make a
partial distribution of available assets to all Credit Bancorp customers, after
payment of administrative expenses, taxes and margin loans secured by valid
liens on securities in Credit Bancorp accounts. Under the Plan, the amount of
the Company's claim would be determined on the basis of the value of the
deposited stock on the date of deposit, which the receiver has indicated would
be approximately $8.5 million. The SEC has informed the court that at this time
there are insufficient assets owned and controlled by the receivership estate
(even assuming that all customer deposited stock belongs to the receivership) to
pay 100% of customers' claims determined in this manner. The receiver is
seeking, however, to marshal and/or take control over additional assets.

         On June 7, 2000, the Company and the receiver entered into an agreement
which provides for the receiver to use reasonable commercial efforts to return
the Company's treasury shares, which are held in brokerage accounts in the name
of Credit Bancorp, in exchange for a total cash payment of approximately $12.1
million, payable upon delivery of the shares. The Company has recorded a charge
to operations in that amount in the quarter ended April 29, 2000. The Company
also agreed to release Credit Bancorp and the receiver from all claims that the
Company may have against Credit Bancorp relating to the credit facility and the
deposit of the treasury shares. The receiver, on behalf of Credit Bancorp,
agreed to release the Company from all claims for contribution or liability to
the receivership estate or claim to ownership of the Company's deposited
treasury shares. The court approved the agreement on June 14, 2000.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

           Quantitative and qualitative information about market risk was
addressed in Item 7A of the Company's Form 10-K for the fiscal year ended
October 30, 1999. There has been no material changes to that information
required to be disclosed in this Form 10-Q filing, except for the approximately
$5.6 million increase from the October 30, 1999 year end balance due to the mark
to market adjustment of the Company's IIA common stock and warrants.


                                       13
<PAGE>   14

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

         (a)      The Annual Meeting of Stockholders of the Company was held on
                  March 28, 2000 (the "Annual Meeting"), at which there were
                  6,078,571 shares of common stock entitled to vote. The vote of
                  holders of record of shares of the Company's common stock
                  outstanding at the close of business on February 3, 2000 was
                  solicited by proxy pursuant to Regulation 14A under the
                  Securities and Exchange Act of 1934.

         (b)      At the Annual Meeting, stockholders approved the following
                  matters by the vote indicated:

<TABLE>
<CAPTION>
                                                                                     VOTE
                                                                  -------------------------------------------
                                                                     For            Against         Abstained
                                                                  ---------         -------         ---------
         <S>                                                      <C>               <C>             <C>
         Election of Class II Directors
              David S. Lee                                        5,670,261              --          39,981
              Dean O. Morton                                      5,670,161              --          40,081

         Approval of the amendment to the
         Company's 1997 Stock Option Plan to
         increase the number of shares of the
         common stock reserved for issuance
         thereunder from 1,030,000 shares to
         1,180,000 shares                                         4,740,052         941,692          28,498

         Approval of the amendment to the
         Company's 1991 Employee Stock
         Purchase Plan to increase the number of
         shares of common stock reserved for
         issuance thereunder from 900,000 shares to
         1,025,000 shares                                         5,487,736         199,423          23,083

         Ratification of appointment of Ernst &
         Young LLP independent auditors for the
         fiscal year ended October 28, 2000                       5,683,393          10,266          16,583
</TABLE>

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

         (a)      Exhibits:

                  10.1     Amendment to Patent License Agreement dated May 25,
                  2000 between the Company and Lucent Technologies, Inc. +

                  10.2     Agreement dated June 7, 2000 between Carl H.
                  Loewenson, Jr., as the Court-Appointed Receiver for Credit
                  Bancorp, Ltd., and the Company, as approved by the United
                  States District Court for the Southern District of New York on
                  June 14, 2000.

                  10.3     Fourth Supplement to Centigram Communications
                  Corporation Preferred Shares Rights Plan dated as of June 9,
                  2000 between the Company and American Stock Transfer and Trust
                  Company.


                                       14
<PAGE>   15

                  27.1     Financial Data Schedule (for SEC use only)

                  + Confidential treatment requested as to certain portions
                  filed separately with the Securities and Exchange Commission.

         (b)      Report on Form 8-K

                  Current Report on Form 8-K to report potential change of
                  control of the Company filed on June 13, 2000.


                                       15
<PAGE>   16

                                   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.

                                      CENTIGRAM COMMUNICATIONS CORPORATION
                                                  (Registrant)


Date:  June 19, 2000                  By /s/ Robert L. Puette
                                        ----------------------------------------
                                         Robert L. Puette
                                         President and Chief Executive Officer


Date:  June 19, 2000                  By /s/ Thomas E. Brunton
                                        ----------------------------------------
                                         Thomas E. Brunton
                                         Sr. Vice President and
                                         Chief Financial Officer


                                       16