As filed with the Securities and Exchange Commission on July 31, 1998.
                                                      Registration No. 333-11013
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                 --------------
                        POST-EFFECTIVE AMENDMENT NO. 1 TO
                                    FORM S-3
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                 --------------
                                  MASTEC, INC.
             (Exact name of registrant as specified in its charter)
                                 --------------

           FLORIDA                          1623                   65-0829355
(State or other jurisdiction of  (Primary Standard Industrial   (I.R.S. Employer
incorporation or organization)   Classification Code Number) Identification No.)

                              3155 N.W. 77TH AVENUE
                              MIAMI, FL 33122-1205
                                 (305) 599-1800
               (Address, including zip code, and telephone number,
        including area code, of registrant's principal executive offices)

                                 --------------

                              JOSE M. SARIEGO, ESQ.
                     SENIOR VICE PRESIDENT - GENERAL COUNSEL
                                  MASTEC, INC.
                              3155 N.W. 77TH AVENUE
                              MIAMI, FL 33122-1205
                                 (305) 406-1954
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

                                   COPIES TO:
                              STEVEN D. RUBIN, ESQ.
                         STEARNS WEAVER MILLER WEISSLER
                           ALHADEFF & SITTERSON, P.A.
                       150 WEST FLAGLER STREET, SUITE 2200
                              MIAMI, FLORIDA 33130
                                 (305) 789-3517

APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: As soon as
practicable after this Registration Statement becomes effective.
If the only securities being registered on this Form are being offered pursuant
to dividend or interest reinvestment plans, please check the following box.[ ]
If any of the securities being registered on this Form are to be offered on a
delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, please check the following box.[X]
If this Form is filed to register additional securities for an offering pursuant
to Rule 462(b) under the Securities Act, please check the following box and list
the Securities Act registration statement number of the earlier effective
registration statement for the same offering.[ ]
If this Form is a post-effective amendment filed pursuant to Rule 462(c) under
the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering.[ ]
If the delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box.[ ]

         THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE
OR DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE
DATE UNTIL THE REGISTRANT SHALL FILE A FURTHER AMENDMENT WHICH SPECIFICALLY
STATES THAT THIS REGISTRATION STATEMENT WILL THEREAFTER
BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF THE SECURITIES ACT OF 1933,
AS AMENDED, OR UNTIL THIS REGISTRATION STATEMENT
SHALL BECOME EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION,
ACTING PURSUANT TO SAID SECTION 8(A), MAY DETERMINE.

================================================================================



                                  MASTEC, INC.

         On March 29, 1998, MasTec, Inc. was reincorporated from a Delaware
corporation to a Florida corporation. This post-effective amendment is being
filed pursuant to Rule 414 under the Securities Act of 1933, as amended (the
"Act"), so that MasTec, Inc., a Florida corporation, may expressly adopt this
Registration Statement of MasTec, Inc., a Delaware corporation, its predecessor,
as its own registration statement for all purposes of the Act and the Securities
Exchange Act of 1934, as amended.







               PART II. INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 15.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Section 607.0831 of the Florida Business Corporation Act (the "Florida
Act") provides that a director is not personally liable for monetary damages to
the corporation or any person for any statement, vote, decision or failure to
act regarding corporate management or policy, by a director, unless: (a) the
director breached or failed to perform his duties as a director; and (b) the
director's breach of, or failure to perform, those duties constitutes: (i) a
violation of criminal law unless the director had reasonable cause to believe
his conduct was lawful or had no reasonable cause to believe his conduct was
unlawful; (ii) a transaction from which the director derived an improper
personal benefit, either directly or indirectly; (iii) a circumstance under
which the director is liable for an improper distribution; (iv) in a proceeding
by, or in the right of the corporation to procure a judgment in its favor or by
or in the right of a shareholder, conscious disregard for the best interests of
the corporation, or willful misconduct; or (v) in a proceeding by or in the
right of someone other than the corporation or a shareholder, recklessness or an
act or omission which was committed in bad faith or with malicious purpose or in
a manner exhibiting wanton and willful disregard of human rights, safety or
property.

         Section 607.0850 of the Florida Act provides that a corporation shall
have the power to indemnify any person who was or is a party to any proceeding
(other than an action by, or in the right of, the corporation), by reason of the
fact that he is or was a director, officer or employee or agent of the
corporation, against liability incurred in connection with such proceeding if he
acted in good faith and in a manner he reasonably believed to be in, or not
opposed to, the best interests of the corporation and, with respect to any
criminal action or proceeding, had no reasonable cause to believe his conduct
was unlawful. Section 607.0850 also provides that a corporation shall have the
power to indemnify any person, who was or is a party to any proceeding by, or in
the right of, the corporation to procure a judgment in its favor by reason of
the fact that he is or was a director, officer, employee or agent of the
corporation, against expenses and amounts paid in settlement not exceeding, in
the judgment of the board of directors, the estimated expense of litigating the
proceeding to conclusion, actually and reasonably incurred in connection with
the defense or settlement of such proceeding, including any appeal thereof.
Section 607.0850 further provides that such indemnification shall be authorized
if such person acted in good faith and in a manner he reasonably believed to be
in, or not opposed to, the best interests of the corporation, except that no
indemnification shall be made under this provision in respect of any claim,
issue, or matter as to which such person shall have been adjudged to be liable
unless, and only to the extent that, the court in which such proceeding was
brought, or any other court of competent jurisdiction, shall determine upon
application that, despite the adjudication of liability, but in view of all
circumstances of the case, such person is fairly and reasonably entitled to
indemnity for such expenses which such court shall deem proper. Section 607.0850
further provides that to the extent that a director, officer, employee or agent
has been successful on the merits or otherwise in defense of any of the
foregoing proceedings, or in defense of any claim, issue or matter therein, he
shall be indemnified against expenses actually and reasonably incurred by him in
connection therewith. Under Section 607.0850, any indemnification under the
foregoing provisions, unless pursuant to a determination by a court, shall be
made by the corporation only as authorized in the specific case upon a
determination that the indemnification of the director, officer, employee or
agent is proper under the circumstances because he has met the applicable
standard of conduct. Notwithstanding the failure of a corporation to provide
such indemnification, and despite any contrary determination by the corporation
in a specific case, a director, officer, employee or agent of the corporation
who is or was a party to a proceeding may apply for indemnification to the
appropriate court and such court may order indemnification if it determines that
such person is entitled to indemnification under the applicable standard.

                                      II-1






         Section 607.0850 also provides that a corporation shall have the power
to purchase and maintain insurance on behalf of any person who is or was a
director, officer, employee or agent of the corporation against any liability
asserted against him and incurred by him in any such capacity or arising out of
his status as such, whether or not the corporation would have the power to
indemnify him against such liability under the provisions of Section 607.0850.

         The Registrant's Amended and Restated Certificate of Incorporation
provides that the Registrant shall indemnify to the fullest extent authorized by
the Florida Act, each person who is involved in any litigation or other
proceeding because such person is or was a director or officer of the
Registrant, against all expense, loss or liability reasonably incurred or
suffered in connection therewith. The Registrant's Bylaws provide that a
director or officer may be paid expenses incurred in defending any proceeding in
advance of its final disposition upon receipt by the Registrant of an
undertaking, by or on behalf of the director or officer, to repay all amounts so
advanced if it is ultimately determined that such director or officer is not
entitled to indemnification.

         The Registrant has obtained primary and excess insurance policies
insuring the directors and officers of the Registrant and its subsidiaries
against certain liabilities they may incur in their capacity as directors and
officers. Under such policies, the insurer, on behalf of the Registrant, may
also pay amounts for which the Registrant has granted indemnification to the
directors or officers.

ITEM 16.  EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.

The following documents are filed as exhibits to this Registration Statement:

5.1      Opinion of Stearns Weaver Miller Weissler Alhadeff & Sitterson P.A.

23.1     Consent of Coopers & Lybrand L.L.P.*

23.2     Consent of Arthur Andersen L.L.P.*

23.3     Consent of Stearns Weaver Miller Weissler Alhadeff & Sitterson P.A. 
         (included in Exhibit 5.1 above).

24.1     Power of Attorney*

27.1     Financial Data Schedule*

- ------------------------
* Previously filed.

                                      II-2






                                   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-3 and has duly caused this Amendment to
the Registration Statement to be signed on its behalf by the undersigned,
thereunto duly authorized, in the City of Miami, State of Florida, on July 31,
1998.

                                                   MASTEC, INC.

                                                   /S/ STEPHEN D. DANIELS
                                                   -----------------------------
                                                   Stephen D. Daniels
                                                   Senior Vice President-Chief
                                                   Financial Officer (Principal
                                                   Financial and Accounting 
                                                   Officer)

         Pursuant to the requirements of the Securities Act of 1933, this
Amendment to Registration Statement has been signed by the following persons in
the capacities and on the dates indicated.


SIGNATURE TITLE DATE /S/ JORGE MAS Chairman of the Board of Directors, July 31, 1998 - ------------------------------------ President and Chief Executive Officer Jorge Mas (Principal Executive Officer) * Director July 31, 1998 - ------------------------------------ Eliot C. Abbott * Director July 31, 1998 - ------------------------------------ Arthur B. Laffer * Director July 31, 1998 - ------------------------------------ Jose S. Sorzano
* By:/S/ JOSE M. SARIEGO ---------------------------------- (Attorney-in-Fact pursuant to Power of Attorney) II-3 EXHIBIT INDEX 5.1 Opinion of Stearns Weaver Miller Weissler Alhadeff & Sitterson P.A. 23.3 Consent of Stearns Weaver Miller Weissler Alhadeff & Sitterson P.A. (included in Exhibit 5.1 above). II-4
                                                                     EXHIBIT 5.1


                                  LAW OFFICES
           STEARNS WEAVER MILLER WEISSLER ALHADEFF & SITTERSON, P.A.
                            MUSEUM TOWER, SUITE 2200
                            150 WEST FLAGLER STREET
                              MIAMI, FLORIDA 33130
                                    --------
                   MIAMI (305) 789-3200 BROWARD (954) 462-9500
                               FAX (305) 789-3395

                                                   July 31, 1998

Mr. Jose M. Sariego
Senior Vice President - General Counsel
MasTec, Inc.
3155 N.W. 77th Avenue
Miami, Florida 33122-1205

                  Re:      Registration Statement on Form S-3
                           (REGISTRATION NO. 333-11013) OF MASTEC, INC.

Dear Mr. Sariego:

         As counsel to MasTec, Inc., a Florida corporation (the "Corporation"),
we have examined the Articles of Incorporation and Bylaws of the Corporation, as
well as such other documents and proceedings as we have considered necessary for
the purposes of this opinion. We have also examined and are familiar with the
above referenced registration statement relating to the sale by the Corporation
of up to 1,000,000 shares of the Corporation's voting common stock, $.10 par
value (the "Common Stock").

         In rendering this opinion, we have assumed, without independent
investigation: (i) the authenticity of all documents submitted to us as
originals; (ii) the conformity to original documents of all documents submitted
to us as certified or photostatic copies and (iii) the





Mr. Jose M. Sariego
July 31, 1998
Page 2

genuineness of all signatures. In addition, as to questions of fact material to
the opinions expressed herein, we have relied upon such certificates of public
officials, corporate agents and officers of the Corporation and such other
certificates as we deemed relevant.

         Based upon the foregoing, and having regard to legal considerations
which we deem relevant, we are of the opinion that following the issuance and
delivery of the Common Stock by the Corporation, against payment of adequate
consideration therefor to the Corporation, the Common Stock will be validly
issued, fully paid and non-assessable.

         This opinion is intended solely for the Corporation's use in connection
with the registration of the Common Stock and may not be relied upon for any
other purpose or by any other person. This opinion may not be quoted in whole or
in part or otherwise referred to or furnished to any other person except in
response to a valid subpoena. This opinion is limited to the matters expressly
stated herein, and no opinion is implied or may be inferred beyond the matters
expressly stated herein. This opinion is rendered as of the date hereof, and we
assume no obligation to update or supplement such opinion to reflect any facts
or circumstances that may hereafter come to our attention or any changes in
facts or law that may hereafter occur. We hereby consent to the inclusion of
this opinion letter as an exhibit to the Registration Statement.

                                                  Very truly yours,

                                                  STEARNS WEAVER MILLER WEISSLER
                                                  ALHADEFF & SITTERSON, P.A.