UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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) April 24, 2012

NABORS INDUSTRIES LTD.

(Exact name of registrant as specified in its charter)

(441) 292-1510

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report.)

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:

On April 24, 2012, we issued a press release announcing our results of operations for the three-month period ending March 31, 2012. A copy of that release is furnished herewith as Exhibit 99.1 and is incorporated herein by reference.

The press release includes forward-looking statements within the meaning of the Securities Act of 1933 and the Securities Exchange Act of 1934. Such forward-looking statements are subject to risks and uncertainties, as disclosed from time to time in our filings with the Securities and Exchange Commission. As a result of these factors, our actual results may differ materially from those indicated or implied by such forward-looking statements.

We also presented in the press release “non-GAAP” financial measures under Regulation G. We presented our adjusted income (loss) derived from operating activities for all periods presented in the release. The components of adjusted income (loss) derived from operating activities are computed by using amounts that are determined in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Adjusted income (loss) derived from operating activities is computed by subtracting direct costs, general and administrative expenses, and depreciation and amortization from Operating revenues and then adding Earnings (losses) from unconsolidated affiliates (excluding our proportionate share of full-cost ceiling test writedowns recorded by our oil and gas joint venture). As part of the press release information, we have provided a reconciliation of adjusted income (loss) derived from operating activities to income (loss) from continuing operations before income taxes, which is its nearest comparable GAAP financial measure. In addition, we provided a schedule of the impact of the full-cost ceiling test writedown to our Operating revenues and Earnings (losses) from unconsolidated affiliates, Income (loss) from continuing operations, net of tax and our diluted earnings per share.

We included our adjusted income (loss) derived from operating activities in the release because management evaluates the performance of our business units and the consolidated company based on several criteria, including adjusted income (loss) derived from operating activities, and because we believe this financial measure is an accurate reflection of our ongoing profitability. We included the adjusted net income (loss) attributable to Nabors because we believe this non-GAAP financial measure to be more indicative of our ongoing operating results and financial condition.

(d) Exhibits

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 hereunto duly authorized.

EXHIBIT INDEX