SecProbe.io

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549-4631

       DIVISION OF
CORPORATION FINANCE

September 1, 2009
  Mr. James H. Haddox Chief Financial Officer, Quanta Services, Inc. 1360 Post Oak Blvd., Suite 2100 Houston, TX  77056
Re: Quanta Services, Inc.
Form 10-Q for the quarter ended June 30, 2009 File No. 1-13831

Dear Mr. Haddox:

We have reviewed your response to our le tter dated July 13, 2009 and the above noted
filings and have the following comment.  Wh ere indicated, we think you should revise your
document in response to this comment.  If you di sagree, 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.  We may ask you to provide us with supplemental information so we may
better understand your disclosure.  After reviewi ng this information, we may or may not raise
additional comments.
Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure requir ements 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 aspe ct of our review.  Feel free to call us at
the telephone numbers listed at  the end of this letter.

Form 10-Q for the period ended June 30, 2009

Notes to the Consolidated Financial Statements
 Note 9.  Segment Information, page 23

 We have reviewed your response to our previous  comment one in our le tter dated July 13, 2009
as well as the disclosures in your Form 10-Q for the period ended June 30, 2009 and have the
following additional comments:

Mr. James H. Haddox
Quanta Services, Inc.
September 1, 2009 Page 2

• With a view towards future disclosure, plea se provide us with a detailed analysis to
support your conclusion that aggregation of your operating units base d on your divisional
structure is appropriate taki ng into consideration paragra ph 17 of SFAS 131.  We remind
you that operating segments can only be aggr egated if they are economically similar
historically and exhibit similar long-term trends , and thus can be expected to have similar
prospects in the future.  It appears to us  that your different industries may not be
exhibiting similar short-term trends as to num ber, size and duration of contracts.  We ask
that you please provide this analysis in a timely manner prior to filing your Form 10-Q
for the period ending September 30, 2009.
• In future filings please enhance your discus sion regarding how your business is managed
to include information you have previously provided to us such as:
o Each operating unit reports to one of two managers below the CODM;
o Operating units may compete against each  other for a particular job and an
entrepreneurial sprit is encouraged in the individual operating units; however, staff and other resources may be shared among operating units on particular jobs
or contracts;
o Operating units may serve customers in multiple industries but are grouped into
divisions based on their predominant of  type of contracts and customers;
o Work may be allocated among operating un its and divisions by the division
Presidents working together;
o Metrics in addition to reve nues, gross margin, operating income that are used to
evaluate performance, and;
o How you determine compensation and what factors the compensation committee
may utilize.
• We note your disclosure that the predominan t type of work by an individual operating
unit can change as the operating unit may e xpand its service capabilities or develop
market opportunities for different types of work.  In future filings pl ease clearly explain
and quantify, if meaningful, th e changes in predominant work by operating units to help
the reader better understand any changes in your segment results.
• We note your discussion of vari ous factors that can influe nce gross margins.  Please
revise future filings to in clude a more specific and comp rehensive discussion regarding
how changes in these factors impact changes in  your operating results.  Please ensure that
you provide quantified inform ation where practicable.
• We note your disclosure that differences in margins in certain  of your services
contributed to changes in your gross profit.  Please revise future filings to quantify the
impact of these margin differences where practicable.
• We note that revenues in th e electric power services se gment were impacted by a
decrease in revenues from emergency restoration services.  In future filings please further explain why this type of variance occurre d by specifically discussing the underlying
events that led to the emer gency restoration services.
 With regard to the above comments, please provide  us with your proposed future disclosures.

Mr. James H. Haddox
Quanta Services, Inc.
September 1, 2009 Page 3

As appropriate, please respond to these comments  within 10 business days or tell us when
you will provide us with a response.  Please furn ish a letter that keys your responses to our
comments and provides any requested supplementa l information.  Detailed response letters
greatly facilitate our review.  Pl ease file your response letter on EDGAR.  Pl ease understand that
we may have additional comments after re viewing your responses to our comments.

If you have any questions regarding this comm ent, please direct them to Mindy Hooker,
Staff Accountant, at (202) 551-3732, Tricia Ar melin, Senior Staff A ccountant, at (202) 551-
3747, or to the undersigned at (202) 551-3768.
Sincerely,    John Cash Branch Chief