Opinion of Sidley Austin LLP as to income tax matters


Re:		PowerShares DB US Dollar Index Trust
		DB US Dollar Index Master Trust
		Post-Effective Amendment No. 1 to the Registration Statement on Form S-1

We have acted as your counsel in connection with the preparation and filing with the Securities and Exchange Commission (the “SEC”) under the Securities Act of 1933, as amended, of the Post-Effective Amendment No. 1 to the Registration Statement on Form S-1, to be filed with the SEC on or about April 15, 2009 (SEC File No.: 333-150588) (the “Registration Statement”), of PowerShares DB US Dollar Index Trust (the “Trust”) and DB US Dollar Index Master Trust (the “Master Trust”), each a Delaware statutory trust organized in separate series on August 3, 2006 and with respect to each of the two separate series of the Trust (each individually, a “Fund,” and collectively, the “Funds”) and each of the two separate series of the Master Trust (each individually, a “Master Fund,” and collectively, the “Master Funds”).

We have reviewed such documents, questions of law and fact and other matters as we have deemed pertinent for the purpose of this opinion. Based upon the foregoing, we hereby confirm our opinions contained under the heading “Material U.S. Federal Income Tax Considerations” in the Prospectus constituting a part of the Registration Statement that each of the Funds and each of the Master Funds will be classified as a partnership for U.S. federal income tax purposes.

We also advise you that the tax discussion under the captions “The Risks You Face”, paragraphs (23), (24) and (25), “Summary – U.S. Federal Income Tax Considerations,” and “Material U.S. Federal Income Tax Considerations” in the Prospectus constituting a part of the Registration Statement correctly describes the material aspects of the U.S. federal income tax treatment to a United States individual taxpayer, as of the date hereof, of an investment in each Fund and each Master Fund.

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Our opinion represents our best legal judgment with respect to the proper U.S. federal income tax treatment of each Fund and Master Fund and United States individual taxpayers investing in the Funds, based on the materials reviewed. Our opinion assumes the accuracy of the facts as represented in documents reviewed or as described to us and could be affected if any of the facts as so represented or described are inaccurate.