<PAGE>

As filed with the Securities and Exchange Commission on May 3, 2000


                                                          Registration No. 333-

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

                                   FORM S-8

                            REGISTRATION STATEMENT

                                     Under

                          The Securities Act of 1933

                                  ALCOA INC.
              (Exact name of issuer as specified in its charter)


      Pennsylvania                                        25-0317820
(State of Incorporation)                    (I.R.S. Employer Identification No.)


                 201 Isabella Street, Alcoa Corporate Center,
                      Pittsburgh, Pennsylvania 15212-5858
          (Address of principal executive office, including zip code)

          REYNOLDS METALS COMPANY 1999 NONQUALIFIED STOCK OPTION PLAN
          REYNOLDS METALS COMPANY 1996 NONQUALIFIED STOCK OPTION PLAN
          REYNOLDS METALS COMPANY 1992 NONQUALIFIED STOCK OPTION PLAN
          REYNOLDS METALS COMPANY 1987 NONQUALIFIED STOCK OPTION PLAN

                            (Full Titles of Plans)

                             Denis A. Demblowski,
                         Secretary and Senior Counsel
                 201 Isabella Street, Alcoa Corporate Center,
                     Pittsburgh, Pennsylvania  15212-5858
                    (Name and address of agent for service)

  Telephone number of agent for service (412) 553-3856

                        CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                              Proposed         Proposed
Title of                                      Maximum          Maximum
Securities                  Amount            Offering         Aggregate        Amount of
to be                       to be             Price Per        Offering         Registration
Registered                  Registered(1)     Share(2)         Price(2)         Fee
<S>                         <C>               <C>              <C>              <C>

Alcoa Inc. common stock,
$1 par value                5,564,789 shares  $63.75           $354,755,298.75  $93,655.40
</TABLE>

(1)   Pursuant to Rule 416(a), also covers additional securities that may be
offered as a result of stock splits, stock dividends or similar transactions.

(2)   Estimated solely for the purpose of calculating the registration fee,
based on the average of the high and low prices of shares of the
Registrant's common stock as reported on the New York Stock Exchange Composite
Transactions Tape on May 2, 2000.
<PAGE>

                               EXPLANATORY NOTE

On May 3, 2000, Reynolds Metals Company became wholly owned by Alcoa Inc. and
each outstanding share of Reynolds Metals Company common stock was converted
into 1.06 shares of Alcoa common stock. At the same time, each outstanding
Reynolds Metals Company employee stock option was converted into an option to
acquire 1.06 shares of Alcoa common stock. This Registration Statement relates
to 5,564,789 shares of Alcoa common stock, par value $1.00 per share, that may
be issued from time to time under the 1987, 1992, 1996 and 1999 Reynolds Metals
Company Nonqualified Stock Option Plans, beginning May 3, 2000. Of the total of
5,564,789 shares, 402,005 shares are allocated for the 1987 Plan; 2,223,059
shares are allocated for the 1992 Plan; 1,987,341 shares are allocated for the
1996 Plan; and 952,384 shares are allocated for the 1999 Plan.



                                     PART I
     INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

ITEMS 1 AND 2

     Documents containing information specified in Part I will be given or sent
to employees in accordance with Rule 428(b)(1).



                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

     The following documents filed by Alcoa with the Securities and Exchange
Commission are incorporated herein by reference:

     (a)  Annual Report on Form 10-K for the fiscal year ended December 31,
1999;

     (b)  All other reports filed by Alcoa pursuant to Section 13(a) or 15(d) of
the Exchange Act since December 31, 1999; and
<PAGE>

     (c)  The description of Alcoa common stock contained under the heading
"Description of Alcoa Capital Stock" in Alcoa's Registration Statement on Form
S-4 filed December 30, 1999 (File No. 333-93849).

     All documents filed by Alcoa under Sections 13(a), 13(c), 14 or 15(d) of
the Securities Exchange Act of 1934 after the date of this Registration
Statement and before the filing of a post-effective amendment to this
Registration Statement that indicates that all securities offered hereunder have
been sold or that deregisters all such securities then remaining unsold shall be
deemed to be incorporated by reference into this Registration Statement and to
be a part hereof from the date of the filing of such documents.  Any statement
contained in a document incorporated, or deemed to be incorporated, by reference
herein or contained in this Registration Statement shall be deemed to be
modified or superseded for purposes of this Registration Statement to the extent
any statement contained herein or in any subsequently filed document which also
is, or is deemed to be, incorporated by reference herein modifies or supersedes
such statement.  Any such statement so modified or superseded shall not be
deemed to constitute a part hereof except as so modified or superseded.

ITEM 4.  DESCRIPTION OF SECURITIES

     Not applicable.


ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

     The validity of the Common Stock to be issued in connection with the Plans
will be passed upon by Denis A. Demblowski, Esq., Secretary and Senior Counsel
of Alcoa.  Mr. Demblowski is a participant in the stock option plan and various
other employee benefit plans offered to employees of Alcoa.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

     Article V of the By-laws of the Company provides that the Company shall
indemnify, under specified circumstances, persons who were or are directors,
officers or employees of the Company or who served or serve other business
entities at the request of the Company.  Under these By-law provisions, a person
who is wholly successful in defending a claim will be indemnified for any
reasonable expenses.  To the extent a person is not successful in defending a
claim, reasonable expenses of the defense and any liability incurred are to be
indemnified under these provisions only where independent legal counsel or other
disinterested person selected by the Board of Directors determines that such
person acted in good faith and in a manner such person reasonably believed to be
in, or not opposed to, the best interests of the Company, and in addition with
respect to any criminal action or proceeding, had no reasonable cause to believe
the conduct of such person was unlawful.  Any expense incurred with respect to
any claim may be advanced by the Company if the recipient agrees to repay such
amount if it is ultimately determined that such recipient is not to be
indemnified pursuant to Article V.

     The foregoing By-law provisions generally parallel Sections 1741 and 1745
of the Pennsylvania Business Corporation Law ("BCL").  Section 1746 and the By-
laws both also provide that the indemnification provided for therein
<PAGE>

shall not be deemed exclusive of any other rights to which those seeking
indemnification may otherwise be entitled.

     Section 1746 of the BCL and the By-laws provide for increased

indemnification protections for directors, officers and others. Indemnification
may be provided by Pennsylvania corporations in any case except where the act or
failure to act giving rise to the claim for indemnification is determined by a
court to have constituted willful misconduct or recklessness.

     Section 1713 of the BCL also sets forth a framework whereby Pennsylvania
corporations, with the approval of the shareholders, may limit the personal
liability of directors for monetary damages except where the act or omission
giving rise to a claim constitutes self-dealing, willful misconduct or
recklessness.  The section does not apply to a director's responsibility or
liability under a criminal or tax statute and may not apply to liability under
Federal statutes, such as the Federal securities laws.


     The Company's  Articles and By-laws were amended by the shareholders to
implement the increased protections made available to directors under the BCL as
described in the preceding paragraph. Article VIII of the By-laws provides that,
except as prohibited by law,  every director of the Company shall be entitled as
of right to be indemnified by the Company for expenses and any and all liability
paid or incurred by such person by reason of such person  being or having been a
director of the  Company.  Expenses  incurred  with  respect to any claim may be
advanced by the Company,  subject to certain  exceptions.  The shareholders have
also approved a form of indemnity  agreement.  The Company has entered into such
an indemnity agreement with each of its current directors.

     The Company has purchased a three year liability  insurance policy with
an aggregate limit of $100 million,  with certain specified  deductible amounts,
for  liability of directors  and officers and  reimbursement  to the Company for
indemnification provided to directors and officers. The policy has an expiration
date of October  1, 2000 and  provides  liability  insurance  and  reimbursement
coverage for the Company, and its directors and officers,  which is permitted by
the laws of Pennsylvania referred to above.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

     Not applicable.

ITEM 8.  EXHIBITS

Exhibit
Number                          Description


(4)  Alcoa's Articles of Incorporation (incorporated by reference to
     Exhibit 3(a) to Alcoa's Annual Report on Form 10-K for the year ended
     December 31, 1988).

(5)  Opinion of Denis A. Demblowski, Senior Counsel of the Company.



<PAGE>

(15)     Letter from Independent Public Accountants regarding unaudited
         financial information.

(23)(a)  Consent of PricewaterhouseCoopers LLP.

(23)(b)  Consent of Counsel (included as part of Exhibit 5).

(24)     Powers of Attorney of certain officers and directors of the Company.

ITEM 9.  UNDERTAKINGS

         The Registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this Registration Statement:

          (i)  To include any prospectus required by Section 10(a)(3) of the
Securities Act of 1933;

          (ii) To reflect in the  prospectus  any facts or events  arising after
the  effective  date  of  the   Registration   Statement  (or  the  most  recent
post-effective  amendment  thereof)  which,  individually  or in the  aggregate,
represent a fundamental  change in the information set forth in the Registration
Statement.  Notwithstanding the foregoing, any increase or decrease in volume of
securities  offered (if the total dollar value of  securities  offered would not
exceed that which was  registered) and any deviation from the low or high end of
the estimated  maximum offering range may be reflected in the form of prospectus
filed with the  Commission  pursuant  to Rule 424(b) if, in the  aggregate,  the
changes in volume and price  represent  no more than a 20% change in the maximum
aggregate  offering price set forth in the  "Calculation  of  Registration  Fee"
table in the effective registration statement;

          (iii) To include any material  information with respect to the plan of
distribution  not  previously  disclosed  in the  Registration  Statement or any
material change to such information in the Registration Statement;

         Provided,  however,  that paragraphs (1)(i) and (1)(ii) do not apply if
the information  required to be included in a post-effective  amendment by those
paragraphs  is  contained  in periodic  reports  filed with or  furnished to the
Commission  by the  Registrant  pursuant  to Section 13 or Section  15(d) of the
Exchange Act that are incorporated by reference in this Registration Statement.

         (2) That,  for the  purpose  of  determining  any  liability  under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new Registration Statement relating to the securities offered therein, and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof;

         (3) To remove from registration by means of a post-effective  amendment
any of the securities being registered which remain unsold at the termination of
the offering; and
<PAGE>

         (4)  That,  for  purposes  of  determining   any  liability  under  the
Securities Act of 1933, each filing of the  Registrant's  annual report pursuant
to Section  13(a) or Section 15(d) of the Exchange Act that is  incorporated  by
reference in the Registration Statement shall be deemed to be a new Registration
Statement relating to the securities  offered therein,  and the offering of such
securities  at that time shall be deemed to be the  initial  bona fide  offering
thereof.

         Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors,  officers and controlling  persons of
the Company pursuant to the foregoing  provisions described in Item 6 above, the
Company has been  informed  that in the opinion of the  Securities  and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore,  unenforceable. In the event that a claim for indemnification
against  such  liabilities  (other  than the  payment by the Company of expenses
incurred or paid by a director,  officer or controlling person of the Company in
the  successful  defense of any action,  suit or proceeding) is asserted by such
director,  officer or controlling person in connection with the securities being
registered,  the Company  will,  unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.
<PAGE>

                               SIGNATURES

         Pursuant  to the  requirements  of the  Securities  Act  of  1933,  the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized, in the City of Pittsburgh, the Commonwealth of Pennsylvania, on this
3rd day of May, 2000.


                                       ALCOA INC.
                                      (Registrant)



                                    /s/ Robert F. Slagle
                                    ----------------------------------
                                    Robert F. Slagle
                                    Executive Vice President -
                                    Human Resources and
                                    Communications


         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
registration  statement  has been signed below by the  following  persons in the
capacities and on the dates indicated.


     Signature                 Title                             Date
     ---------                 -----                             ----


/s/ Alain J.P. Belda     President and                       May 3, 2000
---------------------    Chief Executive Officer
Alain J.P. Belda         (Principal Executive Officer)

/s/ Richard B. Kelson    Executive Vice President and        May 3, 2000
---------------------    Chief Financial Officer
Richard B. Kelson        (Principal Financial Officer)

/s/ Timothy S. Mock      Vice President and                  May 3, 2000
--------------------     Controller
Timothy S. Mock          (Principal Accounting Officer)



Alain J.P. Belda, Kenneth W. Dam, Joseph T. Gorman, Judith M. Gueron, Sir Ronald
Hampel, Hugh M. Morgan, John P. Mulroney, Paul H. O'Neill, Henry B. Schacht,
Franklin A. Thomas and Marina v.N. Whitman, each as a Director, on May 3, 2000,
by Denis A. Demblowski, their attorney-in-fact.



    /s/ Denis A. Demblowski
    --------------------------
    Denis A. Demblowski
    Attorney-in-fact
<PAGE>

                               INDEX TO EXHIBITS



Exhibit
Number                         Description

4        Alcoa's Articles of Incorporation (incorporated by reference to
         Exhibit 3(a) to Alcoa's Annual Report on Form 10-K for the year ended
         December 31, 1988).

5        Opinion of Denis A. Demblowski, Senior Counsel of the Company.

15       Letter from Independent Public Accountants regarding
         unaudited financial information.

23(a)    Consent of PricewaterhouseCoopers LLP.

23(b)    Consent of Counsel (included in Exhibit 5).

24       Powers of Attorney for certain officers and directors
         of the Company.
[{"type": "S-8", "sequence": "1", "description": "STOCK OPTION PLAN", "secsgml_size_bytes": 17470}]
{"company-data": {"conformed-name": "ALCOA INC", "cik": "0000004281", "assigned-sic": "3334", "irs-number": "250317820", "state-of-incorporation": "PA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-36208", "film-number": "618525"}, "business-address": {"street1": "201 ISABELLA ST", "street2": "ALCOA CORPORATE CTR", "city": "PITTSBURGH", "state": "PA", "zip": "15212", "phone": "4125532576"}, "mail-address": {"street1": "201 ISABELLA ST", "street2": "ALCOA CORPORATE CTR", "city": "PITTSBURGH", "state": "PA", "zip": "15212"}, "former-company": {"former-conformed-name": "ALUMINUM CO OF AMERICA", "date-changed": "19920703"}}
As filed with the Securities and Exchange Commission on May 3, 2000

                                                          Registration No. 333-

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

                                   FORM S-8

                            REGISTRATION STATEMENT

                                     Under

                          The Securities Act of 1933

                                  ALCOA INC.
              (Exact name of issuer as specified in its charter)

      Pennsylvania                                        25-0317820
(State of Incorporation)                    (I.R.S. Employer Identification No.)

                 201 Isabella Street, Alcoa Corporate Center,
                      Pittsburgh, Pennsylvania 15212-5858
          (Address of principal executive office, including zip code)

          REYNOLDS METALS COMPANY 1999 NONQUALIFIED STOCK OPTION PLAN
          REYNOLDS METALS COMPANY 1996 NONQUALIFIED STOCK OPTION PLAN
          REYNOLDS METALS COMPANY 1992 NONQUALIFIED STOCK OPTION PLAN
          REYNOLDS METALS COMPANY 1987 NONQUALIFIED STOCK OPTION PLAN

                            (Full Titles of Plans)

                             Denis A. Demblowski,
                         Secretary and Senior Counsel
                 201 Isabella Street, Alcoa Corporate Center,
                     Pittsburgh, Pennsylvania  15212-5858
                    (Name and address of agent for service)

  Telephone number of agent for service (412) 553-3856

                        CALCULATION OF REGISTRATION FEE
Proposed         Proposed
Title of                                      Maximum          Maximum
Securities                  Amount            Offering         Aggregate        Amount of
to be                       to be             Price Per        Offering         Registration
Registered                  Registered(1)     Share(2)         Price(2)         Fee
Alcoa Inc. common stock,
$1 par value                5,564,789 shares  $63.75           $354,755,298.75  $93,655.40
(1)   Pursuant to Rule 416(a), also covers additional securities that may be
offered as a result of stock splits, stock dividends or similar transactions.

(2)   Estimated solely for the purpose of calculating the registration fee,
based on the average of the high and low prices of shares of the
Registrant's common stock as reported on the New York Stock Exchange Composite
Transactions Tape on May 2, 2000.
EXPLANATORY NOTE

On May 3, 2000, Reynolds Metals Company became wholly owned by Alcoa Inc. and
each outstanding share of Reynolds Metals Company common stock was converted
into 1.06 shares of Alcoa common stock. At the same time, each outstanding
Reynolds Metals Company employee stock option was converted into an option to
acquire 1.06 shares of Alcoa common stock. This Registration Statement relates
to 5,564,789 shares of Alcoa common stock, par value $1.00 per share, that may
be issued from time to time under the 1987, 1992, 1996 and 1999 Reynolds Metals
Company Nonqualified Stock Option Plans, beginning May 3, 2000. Of the total of
5,564,789 shares, 402,005 shares are allocated for the 1987 Plan; 2,223,059
shares are allocated for the 1992 Plan; 1,987,341 shares are allocated for the
1996 Plan; and 952,384 shares are allocated for the 1999 Plan.

                                     PART I
     INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

ITEMS 1 AND 2

     Documents containing information specified in Part I will be given or sent
to employees in accordance with Rule 428(b)(1).

                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

     The following documents filed by Alcoa with the Securities and Exchange
Commission are incorporated herein by reference:

     (a)  Annual Report on Form 10-K for the fiscal year ended December 31,
1999;

     (b)  All other reports filed by Alcoa pursuant to Section 13(a) or 15(d) of
the Exchange Act since December 31, 1999; and
(c)  The description of Alcoa common stock contained under the heading
"Description of Alcoa Capital Stock" in Alcoa's Registration Statement on Form
S-4 filed December 30, 1999 (File No. 333-93849).

     All documents filed by Alcoa under Sections 13(a), 13(c), 14 or 15(d) of
the Securities Exchange Act of 1934 after the date of this Registration
Statement and before the filing of a post-effective amendment to this
Registration Statement that indicates that all securities offered hereunder have
been sold or that deregisters all such securities then remaining unsold shall be
deemed to be incorporated by reference into this Registration Statement and to
be a part hereof from the date of the filing of such documents.  Any statement
contained in a document incorporated, or deemed to be incorporated, by reference
herein or contained in this Registration Statement shall be deemed to be
modified or superseded for purposes of this Registration Statement to the extent
any statement contained herein or in any subsequently filed document which also
is, or is deemed to be, incorporated by reference herein modifies or supersedes
such statement.  Any such statement so modified or superseded shall not be
deemed to constitute a part hereof except as so modified or superseded.

ITEM 4.  DESCRIPTION OF SECURITIES

     Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

     The validity of the Common Stock to be issued in connection with the Plans
will be passed upon by Denis A. Demblowski, Esq., Secretary and Senior Counsel
of Alcoa.  Mr. Demblowski is a participant in the stock option plan and various
other employee benefit plans offered to employees of Alcoa.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

     Article V of the By-laws of the Company provides that the Company shall
indemnify, under specified circumstances, persons who were or are directors,
officers or employees of the Company or who served or serve other business
entities at the request of the Company.  Under these By-law provisions, a person
who is wholly successful in defending a claim will be indemnified for any
reasonable expenses.  To the extent a person is not successful in defending a
claim, reasonable expenses of the defense and any liability incurred are to be
indemnified under these provisions only where independent legal counsel or other
disinterested person selected by the Board of Directors determines that such
person acted in good faith and in a manner such person reasonably believed to be
in, or not opposed to, the best interests of the Company, and in addition with
respect to any criminal action or proceeding, had no reasonable cause to believe
the conduct of such person was unlawful.  Any expense incurred with respect to
any claim may be advanced by the Company if the recipient agrees to repay such
amount if it is ultimately determined that such recipient is not to be
indemnified pursuant to Article V.

     The foregoing By-law provisions generally parallel Sections 1741 and 1745
of the Pennsylvania Business Corporation Law ("BCL").  Section 1746 and the By-
laws both also provide that the indemnification provided for therein
shall not be deemed exclusive of any other rights to which those seeking
indemnification may otherwise be entitled.

     Section 1746 of the BCL and the By-laws provide for increased

indemnification protections for directors, officers and others. Indemnification
may be provided by Pennsylvania corporations in any case except where the act or
failure to act giving rise to the claim for indemnification is determined by a
court to have constituted willful misconduct or recklessness.

     Section 1713 of the BCL also sets forth a framework whereby Pennsylvania
corporations, with the approval of the shareholders, may limit the personal
liability of directors for monetary damages except where the act or omission
giving rise to a claim constitutes self-dealing, willful misconduct or
recklessness.  The section does not apply to a director's responsibility or
liability under a criminal or tax statute and may not apply to liability under
Federal statutes, such as the Federal securities laws.

     The Company's  Articles and By-laws were amended by the shareholders to
implement the increased protections made available to directors under the BCL as
described in the preceding paragraph. Article VIII of the By-laws provides that,
except as prohibited by law,  every director of the Company shall be entitled as
of right to be indemnified by the Company for expenses and any and all liability
paid or incurred by such person by reason of such person  being or having been a
director of the  Company.  Expenses  incurred  with  respect to any claim may be
advanced by the Company,  subject to certain  exceptions.  The shareholders have
also approved a form of indemnity  agreement.  The Company has entered into such
an indemnity agreement with each of its current directors.

     The Company has purchased a three year liability  insurance policy with
an aggregate limit of $100 million,  with certain specified  deductible amounts,
for  liability of directors  and officers and  reimbursement  to the Company for
indemnification provided to directors and officers. The policy has an expiration
date of October  1, 2000 and  provides  liability  insurance  and  reimbursement
coverage for the Company, and its directors and officers,  which is permitted by
the laws of Pennsylvania referred to above.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

     Not applicable.

ITEM 8.  EXHIBITS

Exhibit
Number                          Description

(4)  Alcoa's Articles of Incorporation (incorporated by reference to
     Exhibit 3(a) to Alcoa's Annual Report on Form 10-K for the year ended
     December 31, 1988).

(5)  Opinion of Denis A. Demblowski, Senior Counsel of the Company.
(15)     Letter from Independent Public Accountants regarding unaudited
         financial information.

(23)(a)  Consent of PricewaterhouseCoopers LLP.

(23)(b)  Consent of Counsel (included as part of Exhibit 5).

(24)     Powers of Attorney of certain officers and directors of the Company.

ITEM 9.  UNDERTAKINGS

         The Registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this Registration Statement:

          (i)  To include any prospectus required by Section 10(a)(3) of the
Securities Act of 1933;

          (ii) To reflect in the  prospectus  any facts or events  arising after
the  effective  date  of  the   Registration   Statement  (or  the  most  recent
post-effective  amendment  thereof)  which,  individually  or in the  aggregate,
represent a fundamental  change in the information set forth in the Registration
Statement.  Notwithstanding the foregoing, any increase or decrease in volume of
securities  offered (if the total dollar value of  securities  offered would not
exceed that which was  registered) and any deviation from the low or high end of
the estimated  maximum offering range may be reflected in the form of prospectus
filed with the  Commission  pursuant  to Rule 424(b) if, in the  aggregate,  the
changes in volume and price  represent  no more than a 20% change in the maximum
aggregate  offering price set forth in the  "Calculation  of  Registration  Fee"
table in the effective registration statement;

          (iii) To include any material  information with respect to the plan of
distribution  not  previously  disclosed  in the  Registration  Statement or any
material change to such information in the Registration Statement;

         Provided,  however,  that paragraphs (1)(i) and (1)(ii) do not apply if
the information  required to be included in a post-effective  amendment by those
paragraphs  is  contained  in periodic  reports  filed with or  furnished to the
Commission  by the  Registrant  pursuant  to Section 13 or Section  15(d) of the
Exchange Act that are incorporated by reference in this Registration Statement.

         (2) That,  for the  purpose  of  determining  any  liability  under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new Registration Statement relating to the securities offered therein, and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof;

         (3) To remove from registration by means of a post-effective  amendment
any of the securities being registered which remain unsold at the termination of
the offering; and
(4)  That,  for  purposes  of  determining   any  liability  under  the
Securities Act of 1933, each filing of the  Registrant's  annual report pursuant
to Section  13(a) or Section 15(d) of the Exchange Act that is  incorporated  by
reference in the Registration Statement shall be deemed to be a new Registration
Statement relating to the securities  offered therein,  and the offering of such
securities  at that time shall be deemed to be the  initial  bona fide  offering
thereof.

         Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors,  officers and controlling  persons of
the Company pursuant to the foregoing  provisions described in Item 6 above, the
Company has been  informed  that in the opinion of the  Securities  and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore,  unenforceable. In the event that a claim for indemnification
against  such  liabilities  (other  than the  payment by the Company of expenses
incurred or paid by a director,  officer or controlling person of the Company in
the  successful  defense of any action,  suit or proceeding) is asserted by such
director,  officer or controlling person in connection with the securities being
registered,  the Company  will,  unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.
SIGNATURES

         Pursuant  to the  requirements  of the  Securities  Act  of  1933,  the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized, in the City of Pittsburgh, the Commonwealth of Pennsylvania, on this
3rd day of May, 2000.

                                       ALCOA INC.
                                      (Registrant)

                                    /s/ Robert F. Slagle
                                    ----------------------------------
                                    Robert F. Slagle
                                    Executive Vice President -
                                    Human Resources and
                                    Communications

         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
registration  statement  has been signed below by the  following  persons in the
capacities and on the dates indicated.

     Signature                 Title                             Date
     ---------                 -----                             ----

/s/ Alain J.P. Belda     President and                       May 3, 2000
---------------------    Chief Executive Officer
Alain J.P. Belda         (Principal Executive Officer)

/s/ Richard B. Kelson    Executive Vice President and        May 3, 2000
---------------------    Chief Financial Officer
Richard B. Kelson        (Principal Financial Officer)

/s/ Timothy S. Mock      Vice President and                  May 3, 2000
--------------------     Controller
Timothy S. Mock          (Principal Accounting Officer)

Alain J.P. Belda, Kenneth W. Dam, Joseph T. Gorman, Judith M. Gueron, Sir Ronald
Hampel, Hugh M. Morgan, John P. Mulroney, Paul H. O'Neill, Henry B. Schacht,
Franklin A. Thomas and Marina v.N. Whitman, each as a Director, on May 3, 2000,
by Denis A. Demblowski, their attorney-in-fact.

    /s/ Denis A. Demblowski
    --------------------------
    Denis A. Demblowski
    Attorney-in-fact
INDEX TO EXHIBITS

Exhibit
Number                         Description

4        Alcoa's Articles of Incorporation (incorporated by reference to
         Exhibit 3(a) to Alcoa's Annual Report on Form 10-K for the year ended
         December 31, 1988).

5        Opinion of Denis A. Demblowski, Senior Counsel of the Company.

15       Letter from Independent Public Accountants regarding
         unaudited financial information.

23(a)    Consent of PricewaterhouseCoopers LLP.

23(b)    Consent of Counsel (included in Exhibit 5).

24       Powers of Attorney for certain officers and directors
         of the Company.