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	SEC FILE NUMBER
	1-2199
	CUSIP NUMBER

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

FORM 12b-25

NOTIFICATION OF LATE FILING

(Check one):		o  Form 10-K o  Form 20-F o  Form 11-K þ  Form 10-Q o  Form 10-D o  Form N-SAR o  Form N-CSR
		For Period Ended:		June 30, 2011
		o   Transition Report on Form 10-K
		o   Transition Report on Form 20-F
		o   Transition Report on Form 11-K
		o   Transition Report on Form 10-Q
		o   Transition Report on Form N-SAR
		For the Transition Period Ended:

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:

PART I — REGISTRANT INFORMATION

Allis-Chalmers Energy Inc.

Full Name of Registrant

N/A

Former Name if Applicable

11125 Equity Drive, Suite 200

Address of Principal Executive Office (Street and Number)

Houston, TX 77041

City, State and Zip Code

PART II — RULES 12b-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

o
			(a)		The reason described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense
			(b)		The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-SAR or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and
			(c)		The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.

PART III — NARRATIVE

State below in reasonable detail why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-SAR, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

On July 25, 2011, the management of Allis-Chalmers Energy Inc., a Delaware corporation (“Registrant”), concluded that the Registrant’s financial statements for the year ended December 31, 2010 included in the Registrant’s Annual Report on Form 10-K (the “2010 Form 10-K”) need to be restated after further considering certain aspects of the Registrant’s tax accounts for this period.

As a result of the restatement, the Registrant has determined that it is unable to file the Form 10-Q by the prescribed due date without unreasonable effort or expense and does not anticipate filing the Form 10-Q on or before the fifth calendar day following the prescribed due date. Additionally, the restatement has further delayed the filing of the Registrant’s Form 10-Q for the period ending March 31, 2011. The Registrant is working diligently to complete and file the restated 2010 Form 10-K and both Form 10-Qs, but at this time the Registrant is unable to determine when those filings will occur.

		Persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

(Attach extra Sheets if Needed)
PART IV — OTHER INFORMATION

(1)

Name and telephone number of person to contact in regard to this notification

Max Bouthillette		(713)		856-4222
(Name)		(Area Code)		(Telephone Number)

(2)		Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If answer is no, identify report(s).
		Yes  o     No þ

(3)		Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof?
		Yes þ     No o

		If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

The Registrant anticipates that for the three and six months ended June 30, 2011 (the “Current Periods”), revenues will be greater than revenues for the corresponding periods in the prior year (the “Prior Periods”). Revenues in the current periods will not be affected by the restatement. The results in the current periods may be impacted by additional review procedures being performed in connection with the restatement. We have not provided an estimate of such changes because our financial statements have not been finalized.

Cautionary Note about Forward-Looking Statements. This Notification of Late Filing on Form 12b-25 contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934. These statements can be identified by the use of forward-looking words, including “may”, “expect”, “anticipate”, “plan”, “project”, “believe”, “estimate”, “intend”, “will”, “should” or other similar words. Statements contained in this Form 12b-25 are based upon information presently available to the Company and assumptions that it believes to be reasonable. The Company is not assuming any duty to update this information should those facts change or should it no longer believe the assumptions to be reasonable. Investors are cautioned that all such statements involve risks and uncertainties, including without limitation, statements concerning the filing of the Form 10-Q Quarterly Report. The Company’s actual decisions, performance, and results may differ materially.

(Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.

Date		August 9, 2011		By		/s/ Christoph Bausch
						Christoph Bausch
						Chief Financial Officer