UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

Current Report

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

DATE OF REPORT (DATE OF EARLIEST EVENT REPORTED): November 5, 2013

PETROQUEST ENERGY, INC.

(Exact name of registrant as specified in its charter)

Commission File Number: 001-32681

Registrant’s telephone number, including area code: (337) 232-7028

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Item 2.02 RESULTS OF OPERATIONS AND FINANCIAL CONDITION

LAFAYETTE, LA – November 5, 2013—PetroQuest Energy, Inc. (NYSE: PQ) today announced results for the third quarter ended September 30, 2013, which include the effect of its acquisition of certain shallow water Gulf of Mexico assets (the “Acquired Assets”) for an adjusted purchase price of approximately $188 million on July 3, 2013. The following bullets compare certain of the Company’s third quarter 2013 results to those of the second quarter of 2013 highlighting the impact of the acquisition:

Net income available to common stockholders for the quarter ended September 30, 2013 totaled $383,000, or $0.01 per share, compared to third quarter 2012 net loss available to common stockholders of $38,639,000, or $0.62 per share. For the first nine months of 2013, the Company reported net income available to common stockholders of $6,652,000, or $0.10 per share, compared to net loss available to common stockholders of $111,767,000, or $1.79 per share, for the first nine months of 2012. Net loss for the three and nine month 2012 periods included ceiling test writedowns totaling $35,391,000 and $108,987,000, respectively.

Discretionary cash flow for the third quarter of 2013 was $26,717,000, as compared to $17,339,000 for the comparable 2012 period. Net cash flow provided by operating activities totaled $12,294,000 and $25,408,000 during the third quarters of 2013 and 2012, respectively. For the first nine months of 2013, discretionary cash flow was $65,158,000. Discretionary cash flow for the first nine months of 2012 was $57,055,000. Net cash flow provided by operating activities totaled $32,909,000 and $67,676,000 during the first nine months of 2013 and 2012, respectively. See the attached schedule for a reconciliation of net cash flow provided by operating activities to discretionary cash flow.

Production for the third quarter of 2013 was 10.9 Bcfe, a 28% increase from the 8.5 Bcfe produced during the comparable period of 2012. Oil and natural gas liquids production for the third quarter of 2013 increased 79% and 39%, respectively, from the comparable period of 2012. Oil and natural gas liquids production was approximately 23% of the total production for the third quarter of 2013 as compared to 19% for the year-ago quarter. For the first nine months of 2013, production was 27.8 Bcfe compared to 25.1 Bcfe for the comparable period of 2012.

Stated on an Mcfe basis, unit prices received during the third quarter and the first nine months of 2013 were 28% and 13% higher, respectively, than the comparable 2012 periods. Oil and gas sales during the third quarter of 2013 increased 64% to $55,578,000, as compared to $33,913,000 in the third quarter of 2012. For the first nine months of 2013, oil and gas sales increased 26% to $129,630,000 from $103,286,000 in the first nine months of 2012.

Lease operating expenses for the third quarter of 2013 were $1.16 per Mcfe as compared to $1.13 per Mcfe in the third quarter of 2012. For the first nine months of 2013, lease operating expenses per Mcfe were $1.12 as compared to $1.13 in the comparable period of 2012.

Depreciation, depletion and amortization (“DD&A”) on oil and gas properties for the third quarter of 2013 was $2.03 per Mcfe as compared to $1.73 per Mcfe in the third quarter of 2012. The increase in DD&A is primarily the result of the impact of the purchase price of the Acquired Assets. For the first nine months of 2013, DD&A per Mcfe was $1.76 as compared to $1.80 per Mcfe for the comparable period of 2012.

Interest expense for the third quarter of 2013 increased to $8,071,000, as compared to $2,338,000 in the third quarter of 2012. For the first nine months of 2013, interest expense was $14,051,000, compared to $7,021,000 for the comparable period of 2012. The increase in interest expense was the result of the issuance of $200 million of 10% senior notes due 2017, which were used to finance the purchase of the Acquired Assets.

General and administrative expenses increased $3,169,000 and $2,658,000 for the third quarter and nine months ended September 30, 2013, as compared to the respective 2012 periods. General and administrative expenses for the 2013 periods included approximately $2,900,000 in acquisition costs related to the purchase of the Acquired Assets. In addition, during the third quarter of 2013, the Company recognized approximately $1,000,000 in general and administrative expenses associated with benefits due under the compensation agreements of the Company’s Executive Vice President & General Counsel, who passed away unexpectedly in September 2013.

Production taxes for the third quarter of 2013 totaled $1,248,000, as compared to $880,000 in the third quarter of 2012. For the first nine months of 2013, production taxes were $3,757,000 compared to $112,000 for the comparable period of 2012. Production taxes during 2012 were lower as a result of recording a receivable of $2,717,000 during the second quarter of 2012 for refunds relative to production taxes previously paid on Oklahoma horizontal wells.

The following table sets forth certain information with respect to the oil and gas operations of the Company for the three-and nine-month periods ended September 30, 2013 and 2012:

The above sales and average sales prices include increases (decreases) to revenue related to the settlement of gas hedges of $767,000 and $1,482,000, Ngl hedges of $5,000 and $312,000 and oil hedges of ($538,000) and $491,000 for the three months ended September 30, 2013 and 2012, respectively. The above sales and average sales prices include increases (reductions) to revenue related to the settlement of gas hedges of $422,000 and $6,867,000, Ngl hedges of $5,000 and $544,000, and oil hedges of ($684,000) and $853,000 for the nine months ended September 30, 2013 and 2012, respectively.

The following initiates guidance for the fourth quarter of 2013:

Production volumes forecasted for the fourth quarter have been negatively impacted by maintenance on one of the three producing La Cantera wells, downtime due to Tropical Storm Karen in October and downstream third party pipeline work at West Delta 89. Production from La Cantera has been fully restored and the pipeline work at West Delta 89 has been completed.

2014 Guidance

The Company reiterates its previously issued production and capital expenditure guidance for 2014. The Company expects to provide updated guidance, including detailed cost guidance for 2014, in connection with the announcement of its final 2013 proved reserves.

Operations Update

In the Gulf Coast, the Company’s Tokay prospect located at its Ship Shoal 72 field has reached total depth. The Company has an approximate 80% net revenue interest in the well, which encountered six separate pay intervals and logged a total of 209 net feet of pay. The well was recently completed and is expected to achieve a maximum 24 hour gross production rate of 400—600 Bbls of oil per day.

The Company expects to spud its Sawgrass prospect in approximately three weeks. This liquids rich onshore prospect is located in Terrebonne Parish, LA and is expected to reach total depth at the end of the year. The Company has an approximate 57% working interest in this well.

The Company continues to move forward with finalizing drilling plans for its Thunder Bayou prospect, located approximately two miles north of its La Cantera discovery. The Company is in discussions with potential partners to determine the final participation levels in the project and is evaluating drilling rigs and related service providers with expectations to spud this potentially high impact well near the end of the year or in early January 2014. The Company expects to have an approximate 50% working interest in the Thunder Bayou prospect.

During the third quarter, the operator experienced a substantial delay in receiving final regulatory approvals to commence production from two oil wells (NRI—18%) at Ship Shoal 238. The Company originally expected production to commence in mid-August. However, final permits were not received until mid-September and production was initiated at the end of September at a 24 hour gross rate of approximately 1,400 Boe/d (90% oil), limited by the need for additional facility modifications. The Company is in the process of upgrading the topside production equipment on the non-operated host platform. Once work is completed in approximately four weeks, the Company expects the total gross production rate from these two wells will increase to its original estimate of approximately 3,000 Boe/d (90% oil).

At West Delta 89, the Company previously forecasted two recompletions to be online by the end of August 2013. During September, the Company successfully completed the first of the two scheduled recompletions. While performing the second recompletion, the Company encountered a down-hole obstruction which has significantly delayed the commencement of production from the larger of the two recompletions. The Company expects to finish the recompletion within two weeks and initiate production which was previously scheduled for September.

In the Woodford, the Company has commenced drilling on its first pad on the recently acquired rich gas acreage on the western portion of its leasehold position. The five well pad (avg NRI-39%) is expected to be completed in late January 2014 as part of the expected 50 gross well Woodford drilling campaign for 2014. The Company continues to successfully add to its rich gas acreage position and has now acquired in excess of 25,000 net JV acres during 2013, bringing its total rich gas acreage to approximately 30,000 net JV acres.

In East Texas, the Company is actively preparing for a significant increase to its horizontal Cotton Valley program. Permitting and drilling location preparation have commenced at several of the proposed 2014 sites. The Company expects to take delivery of an operated rig in January of 2014 with drilling to commence shortly thereafter. The Company expects to drill 8 to 10 horizontal Cotton Valley wells in 2014 compared to one well in 2013.

In the Mississippian Lime, the Company recently commenced its Pawnee County 3-D seismic survey. The Company expects to receive this data set in late January 2014. The future development plans will be decided after thoroughly analyzing well results with the Kay and Pawnee seismic data packages. In addition, the Company is currently participating in a non-operated Mississippian Lime well in Kay County and is monitoring industry Woodford Shale drilling results in the area.

Hedging Update

The Company recently initiated the following commodity hedging transactions:

The Company has approximately 124,000 barrels of oil, 4.1 Bcf of gas and 14,000 barrels of NGLs hedged for the remainder of 2013 at an average floor price of $102.45 /Bbl, $3.63/Mcf and $92.42/Bbl, respectively. In addition, the Company has approximately 310,000 barrels of oil and 7.3 Bcf of gas hedged for 2014 at an average floor price of $97.91/Bbl and $4.04/Mcf, respectively.

Borrowing Base Update

The Company’s lenders have completed their semi-annual redetermination of the borrowing base under the revolving credit facility. The bank group reaffirmed the Company’s recently increased borrowing base of $200 million, subject to the aggregate commitments of the lenders, which presently total $150 million at the Company’s request. The next re-determination of the borrowing base is expected to occur on or before March 31, 2014.

Management Statement

“Our Tokay discovery builds upon our recent Gulf Coast successes and reinforces our strategic vision that successful Gulf Coast exploitation activities, combined with our fully developed, producing Gulf of Mexico acquisition, will generate substantial free cash flow to be deployed to develop of our onshore assets,” said Charles T. Goodson, Chairman, Chief Executive Officer and President. “The minor start up issues that we have experienced have no impact on reservoir quality, reserve estimates or our outlook on our 2014 liquids production profile, which we are forecasting to average approximately 3,000 barrels of oil per day and 3,800 barrels of NGLs per day, and we expect to have the acquired Gulf of Mexico assets fully integrated in short order.”

About the Company

PetroQuest Energy, Inc. is an independent energy company engaged in the exploration, development, acquisition and production of oil and natural gas reserves in the Arkoma Basin, Wyoming, Texas, South Louisiana and the shallow waters of the Gulf of Mexico. PetroQuest’s common stock trades on the New York Stock Exchange under the ticker PQ.

Forward-Looking Statements

This news release 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, as amended. These forward-looking statements are subject to certain risks, trends and uncertainties that could cause actual results to differ materially from those projected. Among those risks, trends and uncertainties are our ability to integrate our recently completed acquisitions with our operations and realize we anticipate benefits from the acquisitions, any unexpected costs or delays in connection with the acquistions, our ability to find oil and natural gas reserves that are economically recoverable, the volatility of oil and natural gas prices and significantly depressed natural gas prices since the middle of 2008, the uncertain economic conditions in the United States and globally, the declines in the values of our properties that have resulted in and may in the future result in additional ceiling test write-downs, our ability to replace reserves and sustain production, our estimate of the sufficiency of our existing capital sources, our ability to raise additional capital to fund cash requirements for future operations, the uncertainties involved in prospect development and property acquisitions or dispositions and in projecting future rates of production or future reserves, the timing of development expenditures and drilling of wells, hurricanes and other natural disasters, changes in laws and regulations as they relate to our operations, including our fracing operations in shale plays or our operations in the Gulf of Mexico, and the operating hazards attendant to the oil and gas business. In particular, careful consideration should be given to cautionary statements made in the various reports PetroQuest has filed with the Securities and Exchange Commission. PetroQuest undertakes no duty to update or revise these forward-looking statements.

Click here for more information: “http://www.petroquest.com/news.html?=BizID=1690&1=1”

PETROQUEST ENERGY, INC.

Consolidated Balance Sheets

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PETROQUEST ENERGY, INC.

Consolidated Statements of Operations

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Consolidated Statements of Cash Flows

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Non-GAAP Disclosure Reconciliation

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.