VANCOUVER, B.C., July 27, 2009 - Augusta Resource Corporation (TSX/NYSE Amex: AZC) (“Augusta” or “the Company”) is pleased to announce it has entered into an underwriting agreement for a bought deal financing with a syndicate of underwriters led by Wellington West Capital Markets Inc. for the issuance of 12,380,000 common shares at a price of Cdn$2.02 per common share for gross proceeds of Cdn$25,007,600.

Augusta has filed a preliminary short form prospectus under the multi-jurisdictional disclosure system relating to the public offering of the common shares in the United States and Canada. The closing of the offering is subject to a number of conditions, including, without limitation, receipt of all regulatory approvals, and closing is expected to occur on or about August 13, 2009. Augusta plans to use the net proceeds of this financing to advance the development of the Rosemont Copper property located in Pima County, Arizona and for general working capital purposes.

Augusta has also agreed to grant the underwriters an over-allotment option, exercisable at any time, in whole or in part, for a period of 30 days following the closing of the offering, to purchase up to an additional 1,857,000 common shares at a price of Cdn$2.02 per common share. If the underwriters fully exercise the over-allotment option, Augusta will receive additional gross proceeds of Cdn$3,751,140.

A preliminary short form prospectus relating to the securities has been filed with Canadian securities authorities, and a registration statement relating to these securities has been filed with the United States Securities and Exchange Commission but has not yet become effective. These securities may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective.

A copy of the preliminary short form prospectus may be obtained from Wellington West Capital Markets Inc. at 145 King Street West, Suite 700, Toronto, Ontario, M5H 1J8.

About Augusta

Augusta is a base metals company focused on advancing the Rosemont Copper deposit near Tucson, Arizona. Rosemont currently hosts a large copper/molybdenum reserve that may account for about 10% of US copper output once in production in late 2011 (for details refer to www.augustaresource.com). The exceptional experience and strength of Augusta’s management team, combined with the developed infrastructure and robust economics of the Rosemont project, will propel Augusta to become a solid mid-tier copper producer by 2012. The Company is traded on the Toronto Stock Exchange and the NYSE Amex under the symbol AZC, and on the Frankfurt Stock Exchange under the symbol A5R.

For additional information please visit www.augustaresource.com or contact:

Meghan Brown

Investor Relations Manager

tel: 604 638 2002

email: mbrown@augustaresource.com

Certain of the statements made and information contained herein and in the documents incorporated by reference may contain forward-looking statements or information within the meaning of the United States Private Securities Litigation Reform Act of 1995 and forward looking statements or information within the meaning of the Securities Act (Ontario). Forward- looking statements or information include statements regarding the expectations and beliefs of management. Forward looking statements or information include, but are not limited to, statements or information with respect to known or unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the Company, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements or information.

Forward-looking statements or information are subject to a variety of risks and uncertainties which could cause actual events or results to differ from those reflected in the forward-looking statements or information, including, without limitation, risks and uncertainties relating to the Company’s plans at its Rosemont Property and other mineral properties, the interpretation of drill results and the estimation of mineral resources and reserves, the geology, grade and continuity of mineral deposits, the possibility that future exploration, development or mining results will not be consistent with the Company’s expectations, metal recoveries, accidents, equipment breakdowns, title matters, labor disputes or other unanticipated difficulties with or interruptions in production and operations, the potential for delays in exploration or development activities or the completion of feasibility studies, the inherent uncertainty of production and cost estimates and the potential for unexpected costs and expenses, commodity price fluctuations, currency fluctuations, failure to obtain adequate financing on a timely basis, the effect of hedging activities, including margin limits and margin calls, regulatory restrictions, including environmental regulatory restrictions and liability, the speculative nature of mineral exploration, dilution, competition, loss of key employees, and other risks and uncertainties, including those described under “Risk Factors Relating to the Company’s Business” in the Company’s Annual Information Form dated March 25, 2009.

Should one or more of these risks and uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described in forward-looking statements. Accordingly, readers are advised not to place undue reliance on forward-looking statements or information. We do not expect to update forward-looking statements or information continually as conditions change, and you are referred to the full discussion of the Company’s business contained in the Company’s reports filed with the securities regulatory authorities in Canada and the United States.