UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

Amendment No. 1

or

Commission file number: 001-34200

PROSHARES TRUST II

(Exact name of registrant as specified in its charter)

c/o ProShare Capital Management LLC

7501 Wisconsin Avenue, Suite 1000

Bethesda, Maryland 20814

(Address of principal executive offices) (Zip Code)

(240) 497-6400

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    x  Yes    ¨  No

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    ¨  Yes    x  No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    x  Yes    ¨  No

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    x  Yes    ¨  No

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act.).    ¨  Yes    x  No

The aggregate market value of the ProShares Ultra DJ-UBS Commodity Fund’s units held by non-affiliates as of June 30, 2010 was $12,188,000. The ProShares Ultra DJ-UBS Commodity Fund had 550,014 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares UltraShort DJ-UBS Commodity Fund’s units held by non-affiliates as of June 30, 2010 was $3,402,000. The ProShares UltraShort DJ-UBS Commodity Fund had 60,003 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares Ultra DJ-UBS Crude Oil Fund’s units held by non-affiliates as of June 30, 2010 was $496,036,500. The ProShares Ultra DJ-UBS Crude Oil Fund had 9,900,004 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares UltraShort DJ-UBS Crude Oil Fund’s units held by non-affiliates as of June 30, 2010 was $51,816,000. The ProShares UltraShort DJ-UBS Crude Oil Fund had 1,870,003 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares Short DJ-UBS Natural Gas Fund’s units held by non-affiliates as of June 30, 2010 was $0. The ProShares Short DJ-UBS Natural Gas Fund had 4 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares Ultra Gold Fund’s units held by non-affiliates as of June 30, 2010 was $209,362,500. The ProShares Ultra Gold Fund had 3,450,014 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares Short Gold Fund’s units held by non-affiliates as of June 30, 2010 was $0. The ProShares Short Gold Fund had 4 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares UltraShort Gold Fund’s units held by non-affiliates as of June 30, 2010 was $71,721,629. The ProShares UltraShort Gold Fund had 3,639,901 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares Ultra Silver Fund’s units held by non-affiliates as of June 30, 2010 was $178,609,500. The ProShares Ultra Silver Fund had 3,950,014 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares UltraShort Silver Fund’s units held by non-affiliates as of June 30, 2010 was $61,021,976. The ProShares UltraShort Silver Fund had 4,294,979 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares Ultra Euro Fund’s units held by non-affiliates as of June 30, 2010 was $16,320,000. The ProShares Ultra Euro Fund had 300,014 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares UltraShort Euro Fund’s units held by non-affiliates as of June 30, 2010 was $462,685,000. The ProShares UltraShort Euro Fund had 22,850,014 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares Ultra Yen Fund’s units held by non-affiliates as of June 30, 2010 was $4,297,500. The ProShares Ultra Yen Fund had 100,014 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares UltraShort Yen Fund’s units held by non-affiliates as of June 30, 2010 was $145,068,000. The ProShares UltraShort Yen Fund had 20,000,014 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares VIX Short-Term Futures Fund’s units held by non-affiliates as of June 30, 2010 was $0. The ProShares VIX Short-Term Futures Fund had 175,005 outstanding units as of February 25, 2011.

The aggregate market value of the ProShares VIX Mid-Term Futures Fund’s units held by non-affiliates as of June 30, 2010 was $0. The ProShares VIX Mid-Term Futures Fund had 100,005 outstanding units as of February 25, 2011.

DOCUMENTS INCORPORATED BY REFERENCE:

None.

EXPLANATORY NOTE

This Amendment No. 1 to the Annual Report on Form 10-K for the fiscal year ended December 31, 2010 of ProShares Trust II (the “Trust”), filed with the U.S. Securities and Exchange Commission on March 1, 2011 (the “Form 10-K”), is being filed to amend Part II, “Item 9A. Controls and Procedures” of the Form 10-K to: (a) reflect that the Trust’s management has evaluated the disclosure controls and procedures both for the individual series level and the Trust taken as a whole, and to include the conclusions of such evaluations; (b) make conforming changes to “Management’s Annual Report on Internal Control Over Financial Reporting,” including clarifying that the scope of the Trust’s certifications applies both to the series level and to the Trust taken as a whole, and that the principal executive officer and principal financial officer are certifying both as to each series and the Trust taken as a whole; and (c) reflect that there were no changes in the Trust’s or the Funds’ internal control over financial reporting that occurred during the quarter ended December 31, 2010 that have materially affected, or are reasonably likely to materially affect, the Trust’s or the Funds’ internal control over financial reporting.

Except as set forth above, no other changes have been made to the Form 10-K, and this Amendment No. 1 does not amend, update or change any other items or disclosure found in the Form 10-K. Further, this Amendment No. 1 does not reflect events that may have occurred after the filing of the Form 10-K.

Part II

Item 9A. Controls and Procedures.

Disclosure Controls and Procedures

Under the supervision and with the participation of the principal executive officer and principal financial officer of the Trust, Trust management has evaluated the effectiveness of the Trust’s and the Funds’ disclosure controls and procedures, and have concluded that the disclosure controls and procedures of the Trust and the Funds (as defined in Rule 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended) were effective, as of December 31, 2010, to provide reasonable assurance that information required to be disclosed in the reports that the Trust files or submits under the 1934 Act on behalf of itself and the Funds is recorded, processed, summarized and reported, within the time periods specified in the applicable rules and forms, and that it is accumulated and communicated to the duly authorized officers of the Trust as appropriate to allow timely decisions regarding required disclosure.

Management’s Annual Report on Internal Control Over Financial Reporting

The Trust’s Management takes responsibility for establishing and maintaining adequate internal control over financial reporting of the Trust and the Funds, as defined in 1934 Act Rules 13a-15(f) and 15d-15(f). The Trust’s and the Funds’ internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with accounting principles generally accepted in the United States of America. Internal control over financial reporting includes those policies and procedures that: (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the Trust and the Funds; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that the Trust’s and the Funds’ receipts and expenditures are being made only in accordance with appropriate authorizations of management of the Trust on behalf of the Trust and the Funds; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of the Trust’s or the Funds’ assets that could have a material effect on the Trust’s or the Funds’ financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

The principal executive officer and principal financial officer of the Trust assessed the effectiveness of the Trust’s and the Funds’ internal control over financial reporting as of December 31, 2010. Their assessment included an evaluation of the design of the Trust’s and the Funds’ internal control over financial reporting and testing of the operational effectiveness of their internal control over financial reporting. In making its assessment, the Trust’s management has utilized the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) in its report entitled Internal Control – Integrated Framework. Based on their assessment and those criteria, the principal executive officer and principal financial officer of the Trust concluded that the Trust’s and the Funds’ internal control over financial reporting was effective as of December 31, 2010.

The effectiveness of the Trust’s and the Funds’ internal control over financial reporting as of December 31, 2010 has been audited by PricewaterhouseCoopers LLP, the independent registered public accounting firm, as stated in their report which is included herein.

Changes in Internal Control over Financial Reporting

There were no changes in the Trust’s or the Funds’ internal control over financial reporting that occurred during the quarter ended December 31, 2010 that have materially affected, or are reasonably likely to materially affect, the Trust’s or the Funds’ internal control over financial reporting.

Exhibit Index

Part IV

Item 15. Exhibits and Financial Statement Schedules.

SIGNATURES

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.