<PAGE>   1


                                    FORM 10-Q

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


              [X] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

                  FOR THE QUARTERLY PERIOD ENDED MARCH 31, 2000

                                       OR

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


                         COMMISSION FILE NUMBER 0-20430


                                AZCO MINING INC.

                            (A DELAWARE CORPORATION)

                I.R.S. Employer Identification Number 84-1094315

                     2068 Main Street Suite C, P.O. Box 1895
                               Ferndale, WA 98248
                                 (360) 380-4467


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

                                  YES X NO ____


Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date: 29,864,121 shares of the
Company's Common Stock were outstanding as of May 11, 2000.


<PAGE>   2




                           AZCO MINING INC. (DELAWARE)



Statements contained in the quarterly report that are not historical facts are
forward-looking statements as that term is defined in the Private Securities
Litigation Reform Act of 1995. Such forward-looking statements are subject to
risks and uncertainties, which could cause actual results to differ materially
from the estimated results. Such risks and uncertainties are detailed in the
Company's filings with the Securities and Exchange Commission.



                          PART I. FINANCIAL INFORMATION



ITEM 1. FINANCIAL STATEMENTS

<TABLE>
<CAPTION>
                                                                            PAGE

         <S>                                                                <C>
         Consolidated Balance Sheets                                           3

         Consolidated Statements of Operations                                 4

         Consolidated Statements of Cash Flows                                 5

         Consolidated Statement of Stockholders' Equity                        6

         Notes to Interim Consolidated Financial Statements                  7-9


</TABLE>

                                       2
<PAGE>   3


AZCO MINING INC. (DELAWARE)
CONSOLIDATED BALANCE SHEETS
(UNAUDITED)

ASSETS
<TABLE>
<CAPTION>

                                                 MARCH 31,      JUNE 30,
                                                   2000          1999
                                               ------------   ------------
CURRENT ASSETS:
<S>                                            <C>            <C>
Cash and cash equivalents                      $  5,923,954   $ 12,106,173
Prepaids and other                                  164,318         95,623
                                               ------------   ------------
  Total current assets                            6,088,272     12,201,796
                                               ------------   ------------
PROPERTY AND EQUIPMENT:
Mineral Properties, plant & equipment             7,465,375      5,076,969
Inventoried mining costs                            873,476
Furniture and equipment                             139,809         74,502
Vehicles                                             81,145
                                               ------------   ------------
                                                  8,559,805      5,151,471
Less accumulated depreciation                      (104,097)       (57,863)
                                               ------------   ------------
                                                  8,455,708      5,093,608
                                               ------------   ------------

Investments and advances                             50,588         50,588
Other assets                                          7,725          7,725
                                               ------------   ------------
                                               $ 14,602,293   $ 17,353,717
                                               ------------   ------------

LIABILITIES AND STOCKHOLDERS' EQUITY

CURRENT LIABILITIES:

Accounts payable and accrued liabilities       $    138,511   $    387,984
                                               ------------   ------------
  Total current liabilities                         138,511        387,984
                                               ------------   ------------


Stockholders' equity
Common stock: $.002 par value, 100,000,000           59,728         59,664
shares authorized:
29,864,121 shares outstanding as of March 31,
2000 and 29,832,121 as of June 30,1999
Additional paid-in capital                       28,320,715     28,297,561
Deficit                                         (13,916,661)   (11,391,492)
                                               ------------   ------------
                                                 14,463,782     16,906,069
                                               ------------   ------------
Total liabilities and stockholders' equity     $ 14,602,293   $ 17,353,717
                                               ============   ============

</TABLE>


                                       3

<PAGE>   4


AZCO MINING INC. (DELAWARE)
CONSOLIDATED STATEMENTS
OF OPERATIONS (UNAUDITED)
<TABLE>
<CAPTION>

                                     THREE MONTHS ENDED            NINE MONTHS ENDED
                                           MARCH 31,                    MARCH 31,
                               ---------------------------   ---------------------------
                                    2000          1999            2000           1999
                               ------------   ------------   ------------   ------------
<S>                            <C>            <C>            <C>            <C>
INCOME:
  Interest income              $    100,737   $    215,818   $    362,108   $    719,636
  Other income                                      11,500        277,500         11,500
                               ------------   ------------   ------------   ------------
                                    100,737        227,318        639,608        731,136
                               ------------   ------------   ------------   ------------
EXPENSES:
  Salaries                          211,077        544,317        634,823        985,022
  General and administrative        256,820        229,434        644,900        710,476
  Exploration                       165,696        239,955        459,362      1,467,836
  Accounting and legal               52,534         74,867        181,946        151,780
  Write-off Calgem loan             250,000                       250,000
  Write-off mica proj
    start-up                        947,511                       947,511
  Amortization and deprec            38,971          3,570         46,234         11,277
                               ------------   ------------   ------------   ------------
                                  1,922,609      1,092,143      3,164,776      3,326,391
                               ------------   ------------   ------------   ------------
Loss before income taxes         (1,821,872)      (864,825)    (2,525,168)    (2,595,255)

  Income taxes                                      (4,186)                       (4,186)
                               ------------   ------------   ------------   ------------
NET LOSS                       $ (1,821,872)  $   (860,639)  $ (2,525,168)  $ (2,591,069)
                               ============   ============   ============   ============

Basic loss per common share    $      (0.06)  $      (0.03)  $      (0.08)  $      (0.10)
                               ============   ============   ============   ============
Diluted loss per common share  $      (0.06)  $      (0.03)  $      (0.08)  $      (0.10)
                               ============   ============   ============   ============
WEIGHTED AVERAGE COMMON
  SHARES                         29,847,681     26,402,745     29,838,034     25,828,510
                               ============   ============   ============   ============
</TABLE>

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


                                       4
<PAGE>   5


AZCO MINING INC. (DELAWARE)
CONSOLIDATED STATEMENTS OF CASH
FLOWS (UNAUDITED)
<TABLE>
<CAPTION>

                                                         NINE MONTHS ENDED
                                                             MARCH 31,
                                                   -----------------------------
                                                        2000            1999
                                                   -------------   -------------
<S>                                                <C>             <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss                                           $ (2,525,168)   $ (2,591,069)
Adjustments to reconcile net loss to net cash
used in operations:
  Stock issued for mineral properties                                   234,375
  Depreciation and amortization                          46,234          11,277
  Stock option compensation expense                                     310,000
  Gain on sale of furniture and equipment                                (1,500)
  Gain on sale of Mali assets                          (277,500)
  Write-off of Calgem loan                              250,000
Changes in assets and liabilities, net:
  Prepaid and other assets                              (68,696)        110,432
  Accounts payable and accrued liabilities             (249,473)       (161,346)
  Income tax receivable                                                  (4,186)
                                                   ------------    ------------
Net cash used for operating activities               (2,824,603)     (2,092,017)
                                                   ------------    ------------
CASH FLOWS FROM INVESTING ACTIVITIES:
  Purchases of furniture and equipment                 (146,452)         (7,486)
  Purchase of mine property, plant and equip         (3,261,882)       (892,290)
  Proceeds from sale of furniture and equip                               1,500
  Proceeds from sale of Mali assets                     277,500
  Investments and advances                             (250,000)     (1,153,569)
                                                   ------------    ------------
Net cash used for investing activities               (3,380,834)     (2,051,845)
                                                   ------------    ------------
CASH FLOWS FROM FINANCING ACTIVITY:
  Proceeds from exercise of options                      23,218
  Purchase of treasury stock                                           (467,374)
                                                   ------------    ------------
Net cash used for financing activity:                    23,218        (467,374)
                                                   ------------    ------------
Net decrease in cash and cash equivalents            (6,182,219)     (4,611,236)

Cash and cash equivalents at beginning of period     12,106,173      18,320,882
                                                   ------------    ------------
Cash and cash equivalents at end of period         $  5,923,954    $ 13,709,646
                                                   ============    ============


</TABLE>

The accompanying notes are an integral part of these financial statements


                                       5
<PAGE>   6


AZCO MINING INC. (DELAWARE)
CONSOLIDATED STATEMENT OF
STOCKHOLDERS' EQUITY
(UNAUDITED)

<TABLE>
<CAPTION>
                                     COMMON                   ADDITIONAL
                                      STOCK                    PAID-IN
                                                               CAPITAL
                             Shares           A m o u n t                       DEFICIT

<S>                          <C>             <C>              <C>              <C>
Balance June 30,1999         29,832,121      $     59,664     $ 28,297,561     $(11,391,493)

Exercise of options              32,000                64           23,154

Net Loss                                                                         (2,525,168)
                             ----------      ------------     ------------     ------------
Balance March 31, 2000       29,864,121      $     59,728     $ 28,320,715     $(13,916,661)
                             ==========      ============     ============     ============
</TABLE>

The accompanying notes are an integral part of these financial statements

                                       6

<PAGE>   7

AZCO MINING INC. (DELAWARE)
NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

NOTE 1. BASIS OF PRESENTATION

In the opinion of management the accompanying interim financial statements
contain all material adjustments consisting only of normal recurring adjustments
necessary to present fairly the financial position, the results of operations
and the cash flows of the Company and its consolidated subsidiaries for the
interim period. Users of financial information produced for interim periods are
encouraged to refer to the footnotes contained in the Annual Report on Form 10-K
when reviewing interim financial results.

Azco Mining Inc. (Delaware) ("AZCO" or the "Company") is a U.S. mining company
with a general business strategy to acquire and develop mineral properties
amenable to low cost production. The Company is currently focused on producing
high quality Muscovite Mica from its 100% owned Black Canyon Mica project
located in Arizona. The Company, with its 30% interest, has also established a
strategic partnership with Phelps Dodge Corporation on the Piedras Verdes copper
project located in Sonora, Mexico. The business strategy on large exploration
projects has been focused on establishing partnerships with major companies.
This strategy generally reduces financial risk and offers the opportunity to
participate in major mineral projects.

NOTE 2. BLACK CANYON MICA PROJECT (ARIZONA)

Construction and commissioning continues on a 10,000-ton per year wet ground
mica processing facility in Glendale, Arizona, approximately 40 miles from the
Black Canyon Mica Mine. Through March 31, 2000 the Company has expended a total
of $9,424,622 on the Mica project. This represents $2,219,996 of acquisition
costs, $6,257,115 of plant construction and mine development costs and a current
period write-off of $947,511 for project start-up costs. Mine development costs
include approximately $873,476 of contract mining and hauling costs that will be
amortized over the first year of actual mine production expected to begin in the
third quarter of calendar 2000. Total plant construction and mine development
costs for the Black Canyon Mica project are currently budgeted at $7,139,000.

The initial contract mining campaign has been completed and 63,010 tons of ore
have been stockpiled at the mine. Initial production of high quality wet ground
muscovite mica is currently underway and the first sales are expected in June of
2000.

                                       7
<PAGE>   8




AZCO MINING INC. (DELAWARE)
NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)
(CONTINUED)

NOTE 3. PIEDRAS VERDES PROJECT (MEXICO)

The Piedras Verdes property is leased by Cobre del Mayo, S.A. de C.V. ("Cobra
del Mayo"), a Mexican corporation that is owned 30% by AZCO and 70% by Minera
Phelps Dodge Mexico S. de R.L. de C.V. ("MPDM"), a subsidiary of Phelps Dodge
Corporation. The property consists of approximately 640 hectares and is located
in southern Sonora State, Mexico.

NOTE 4. MALI PROJECT (NORTHWESTERN AFRICA)

The Company is currently in the second year of a joint venture with Randgold
Resources Limited ("Randgold") whereby Randgold has the right to earn up to 75%
of the Company's interest in West Africa Gold and Exploration S.A. ("WAG"). To
earn this interest Randgold has agreed, over a 36-month period, to conduct
exploration on the WAG property concessions at a minimum cost of $2 million,
with the aim of establishing whether there is a viable economic gold resource,
as defined in the joint venture agreement, of at least one million ounces.
Thereafter Randgold shall prepare a Bankable Feasibility Study on any such
resource for WAG within a further 12 months in order to earn its interest
therein. The Company realized a gain on sale of assets of $277,500 in
conjunction with the joint venture agreement with Randgold when the exploration
camp assets were sold.

NOTE 5. CALGEM INC. AGREEMENT IN PRINCIPLE

Effective on August 9, 1999 the Company entered into an "Agreement in Principle"
(the "AIP") with each of Thomas Ford and Calgem, Inc., a company wholly-owned by
Mr. Ford (collectively, "Calgem"), pursuant to which Calgem therein granted the
Company an option to purchase all of the issued and outstanding shares of Calgem
and/or business assets of Calgem. Calgem is a company that auctions colored
gemstones on television. In accordance with the terms and conditions of the AIP,
as now expired, the Company had advanced, by way of a loan to Calgem (the
"Loan"), an aggregate of $250,000. The Loan, together with interest accruing
thereon at the rate of ten percent per annum, was to be secured by way of a
senior fixed and floating charge on all of the assets of Calgem (the
"Security"). The Company wrote-off the Loan during the current quarter due to
the fact that it had not been successful in contacting Calgem to discuss either
repayment terms or the establishment of the Security for the Loan. The Company,
in discussions with counsel, is currently considering its course of action
against Calgem.

                                       8
<PAGE>   9

AZCO MINING INC. (DELAWARE)
NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)
(CONTINUED)


NOTE 6. INVENTORIED MINING COSTS

During the current quarter $873,476 was reclassified from mineral properties,
plant and equipment to inventoried mining costs. This amount includes $50,620 of
hauling costs incurred to move previously crushed ore from the mine to the
Glendale plant. In addition, $822,856 of contract mining costs was incurred
during the initial mining campaign where 63,010 tons of ore were mined and
stockpiled. These inventoried mining costs will be expensed in the same period
that the ore is processed.

NOTE 7. OUTSTANDING OPTIONS

At March 31, 2000 3,649,500 options to purchase shares of the Company's common
stock were outstanding under the Company's Stock Option Plan. These options are
exercisable between $0.48 and $3.00 per common share at varying dates through
2004.

                                      9
<PAGE>   10




AZCO MINING INC. (DELAWARE)

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

RESULTS OF OPERATIONS

GENERAL

The Company was formed on July 13, 1988. On December 21, 1995 the Company
announced that it had completed the sale of its Sanchez project and a 70%
interest in its Mexican project, the Piedras Verdes, to Phelps Dodge Corporation
for $40 million. All material revenues since the sale have been a result of
interest earned on the proceeds of the sale of assets to Phelps Dodge
Corporation.

The Company is currently focused on the construction of facilities to produce
high quality muscovite mica from its 100% owned Black Canyon Mica project
located in Arizona. The Company, with its 30% interest, has established a
strategic partnership with Phelps Dodge Corporation on the Piedras Verdes copper
project located in Sonora, Mexico.

A pre-feasibility report has been prepared on the Piedras Verdes project and a
$3,600,000 work budget advancing the project towards a bankable feasibility is
currently underway. The report, assuming a copper price of $1.00/ lb., estimates
project-operating costs below $0.50 per pound over a 10-year life with annual
copper production of 130 million pounds.

THREE MONTHS ENDED MARCH 31, 2000 COMPARED TO THREE MONTHS ENDED MARCH 31, 1999.

The net loss for the three months ended March 31, 2000 was $1,821,872 compared
to a net loss of $860,639 for the three months ended March 31, 1999. The
increased net loss was due to the write-off of $947,511 in Mica project start-up
costs and the write-off of the Calgem Loan of $250,000.

Salaries expense was $211,077 for the three months ended March 31, 2000 compared
to $544,317 for the three months ended March 31, 1999. The decrease in salaries
expense for the current period was due to the recording of $310,000 in
compensation expense recognized on stock options granted to non-employees that
was recorded during the quarter ended March 31, 1999.

Depreciation expense was $38,971 for the three months ended March 31, 2000
compared to $3,570 for the three months ended March 31, 1999. The increase in
depreciation expense in the current quarter is due to the initial depreciation
of the Mica project's vehicles and office equipment.

                                       10
<PAGE>   11

AZCO MINING INC. (DELAWARE)


During the three month period ended March 31, 2000 the Company expended an
additional $1,031,300 on the acquisition, development, construction and start-up
of the Mica project, which brings total expenditures on the project to
$9,424,622 to date.

NINE MONTHS ENDED MARCH 31, 2000 COMPARED TO NINE MONTHS ENDED MARCH 31, 1999.

The net loss for the nine months ended March 31, 2000 was $2,525,168 compared to
a net loss of $2,591,069 for the nine months ended March 31, 1999. The net loss
in the current period was partly due to the write-off of $947,511of Mica project
start-up costs and the write-off of the Calgem Loan of $250,000. These losses
are partially offset by higher exploration costs in the nine-month period ended
March 31, 1999.

Salaries expense was $634,823 for the nine months ended March 31, 2000 compared
to $985,022 for the nine months ended March 31, 1999. The decrease in salaries
expense for the current period was due to the recording of $310,000 in
compensation expense recognized on stock options granted to non-employees that
was recorded during the quarter ended March 31, 1999.

Depreciation expense was $46,234 for the nine months ended March 31, 2000
compared to $11,277 for the nine months ended March 31, 1999. The increase in
depreciation expense in the current period is due to the initial depreciation of
Mica project vehicles and office equipment.

FINANCIAL CONDITION

As of March 31, 2000 the Company had cash and cash equivalents of $5,923,954.

The Company believes that for the current fiscal year ended June 30, 2000 all
capital and operating requirements will be funded with present cash and cash
equivalents as well as anticipated revenues from the Mica project.


                                       11
<PAGE>   12

AZCO MINING INC. (DELAWARE)


ITEM 3:  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

         Not applicable.

PART II.  OTHER INFORMATION

ITEM 1:  LEGAL PROCEEDINGS

                  None.

ITEMS 2-3: NOT Applicable

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

On March 1, 2000 the Company held the annual general meeting of shareholders for
the fiscal year ended June 30, 1999. A brief discussion of the matters voted
upon follows:

     1.   Alan P. Lindsay, Anthony R. Harvey, Ian M. Gray, Lawrence G. Olson and
          Paul A. Hodges were elected directors of the Company to hold office
          until the next annual general meeting of the Company or until their
          successors are elected of appointed subject to the provisions of the
          Company's by-laws;

     2.   It was resolved that PricewaterhouseCoopers would serve as the
          Company's auditors for the fiscal year ended June 30, 2000

       The following table states the number of shares cast as to each matter.

<TABLE>
<CAPTION>

                                  In Favor      Against     Withhold    Abstain    Not Voted

<S>                                 <C>                  <C>     <C>      <C>                 <C>
1a Alan P. Lindsay                  22,956,359           0       9,890    242,220             0
1b Anthony R. Harvey                22,949,359           0      16,890    242,220             0
1c Ian M. Gray                      22,926,259           0      39,990    242,220             0
1d Paul A. Hodges                   22,937,859           0      28,390    242,220             0
1e Lawrence G. Olson                22,936,359           0      29,890    242,220             0

2  Appointment of auditors          22,997,971     112,208           0     98,290             0

</TABLE>

ITEM 5:  OTHER INFORMATION

                  None.

                                       12
<PAGE>   13

                           AZCO MINING INC. (DELAWARE)

ITEM 6:  EXHIBITS AND REPORTS ON FORM 8-K

    (a)  Exhibits:
                                    None.

    (b)  Reports on Form 8-K
                                    None.


                                   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 thereunder duly authorized.


Date:  May 11, 2000                  BY:      /s/ Alan P. Lindsay
       -------------                          -------------------
                                              Alan P. Lindsay
                                              CEO, President and Chairman


Date:  May 11, 2000                  BY:      /s/ Ryan A. Modesto
       -------------                          -------------------
                                              Ryan A. Modesto
                                              Vice President Finance



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