December 9, 2005

Alberto de Cardenas
Executive Vice President and General Counsel
MasTec, Inc.
800 Douglas Road, 12th Floor
Coral Gables, Florida 33134

Re:	MasTec, Inc.
	Registration Statement on Form S-1
	Filed on November 18, 2005
	File No. 333-129790

Dear Mr. de Cardenas:

      We have limited our review of your filing to those issues we
have addressed on our comments.  Where indicated, we think you
should
revise your documents in response to these comments.  If you
disagree,
we will consider your explanation as to why our comment is
inapplicable or a revision is unnecessary.  Please be as detailed
as
necessary in your explanation.  In some of our comments, we may
ask
you to provide us with information so we may better understand
your
disclosure.  After reviewing this information, we may raise
additional
comments.

      Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We
look forward to working with you in these respects.  We welcome
any
questions you may have about our comments or on any other aspect
of
our review.  Feel free to call us at the telephone numbers listed
at
the end of this letter.

Prospectus Summary, page 2

1. Please revise to include a balanced description of your
business.
For example, while you discuss your revenues, you do not discuss
your
net loss during those periods.  In addition, please remove the
sections on Our Industry and Competitive Strengths.

Risk Factors, page 7

2. Please provide the information investors need to assess the
magnitude of the risk. For example:
* quantify any recent significant variance between your backlog
and
the revenues you realize; and
* disclose any charges against earnings in 2003 and 2004 resulting
from variations of your assumptions using the percentage-of-
completion
accounting.

Financial Metrics, page 26

3. Please consider whether this information can be made more
useful to
investors if you elaborate you why these items are important to
management, and how well the company performs according to these
criteria.

Business, page 47

4. Please describe the practices of the company and the industry
relating to working capital items (e.g., inventory). See Item
101(c)(1)(vi) of Regulation S-K.

Regulation, page 53

5. Under Regulation, please describe in greater detail the federal
and
state laws that you are required to comply with. In addition,
please
disclose the material effects that compliance with environmental
laws
may have on your financial condition. See Item 101(c)(1)(xii) of
Regulation S-K.

Underwriters, page 75

6. Disclose the criteria that Morgan Stanley will use in
determining
whether to consent to waiving the 90-day lock up agreement.

7. Please identify any members of the underwriting syndicate that
will
engage in any electronic offer, sale, or distribution of the
shares
and describe their procedures to us supplementally, or confirm
that
the Division`s Office of Chief Counsel has reviewed and approved
these
procedures.  If you become aware of any additional members of the
underwriting syndicate that may engage in electronic offers,
sales, or
distributions after you respond to this comment, promptly
supplement
your response to identify those members and provide us with a
description of their procedures.

8. Tell us whether you or the underwriters have any arrangements
with
a third-party to host or access your preliminary prospectus on the
Internet.  If so, identify the party and the website, describe the
material terms of your agreement, and provide us with a copy of
any
written agreement.  Please also provide us with copies of all
information concerning your company or prospectus that has
appeared on
their website.  Again, if you subsequently enter into any such
arrangements, promptly supplement your response.

Where you can find more information about Mastec, page 78

9. Please remove the sentence in the middle of this paragraph that
qualifies statements you make in the prospectus by reference to
information outside of the prospectus.  Rule 411(a) permits this
type
of qualification only where contemplated by the form.

Exhibit 5.1 - Legal Opinion

10. Please file your legal opinion with your next amendment, or as
soon as possible. Please note that we may have comments on the
legal
opinion.

	As appropriate, please amend your filing in response to these
comments.  You may wish
to provide us with marked copies of the amendment to expedite our
review.  Please furnish a cover letter with your amendment that
keys
your responses to our comments and provides any requested
information.
Detailed cover letters greatly facilitate our review.  Please
understand that we may have additional comments after reviewing
your
amendment and responses to our comments.

      We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filings reviewed by the staff to
be
certain that they have provided all information investors require
for
an informed decision.  Since the company and its management are in
possession of all facts relating to a company`s disclosure, they
are
responsible for the accuracy and adequacy of the disclosures they
have
made.

	Notwithstanding our comments, in the event the company
requests
acceleration of the effective date of the pending registration
statement, it should furnish a letter, at the time of such
request,
acknowledging that:

?	should the Commission or the staff, acting pursuant to
delegated
authority, declare the filing effective, it does not foreclose the
Commission from taking any action with respect to the filing;

?	the action of the Commission or the staff, acting pursuant to
delegated authority, in declaring the filing effective, does not
relieve the company from its full responsibility for the adequacy
and
accuracy of the disclosure in the filing; and

?	the company may not assert this action as a defense in any
proceeding initiated by the Commission or any person under the
federal
securities laws of the United States.

	In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division
of Corporation Finance in connection with our review of your
filing or
in response to our comments on your filing.

      We will consider a written request for acceleration of the
effective date of the registration statement as a confirmation of
the
fact that those requesting acceleration are aware of their
respective
responsibilities under the Securities Act of 1933 and the
Securities
Exchange Act of 1934 as they relate to the proposed public
offering of
the securities specified in the above registration statement.  We
will
act on the request and, pursuant to delegated authority, grant
acceleration of the effective date.

	We direct your attention to Rules 460 and 461 regarding
requesting acceleration of a registration statement.  Please allow
adequate time after the filing of any amendment for further review
before submitting a request for acceleration.  Please provide this
request at least two business days in advance of the requested
effective date.

      You may contact Brigitte Lippmann at (202) 551-3713 or me at
(202) 551-3760 if you have any questions.

Sincerely,



Pamela A. Long
Assistant Director

cc:	Paul Berkowitz, Esq.
	Greenberg Traurig, P.A.
	1221 Brickell Avenue
	Miami, Florida 33131


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Alberto de Cardenas
MasTec, Inc.
December 9, 2005
Page 1



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

         DIVISION OF
CORPORATION FINANCE