Vancouver, B.C. MAG Silver Corp. (TSX: MAG; NYSE-A: MVG) (“MAG” or the “Company”) announces an independent updated Mineral Resource estimate for the Juanicipio Property completed by Roscoe Postle Associates Inc. (“RPA”) on behalf of MAG. The updated RPA Mineral Resource estimate is based on drill results available as of August 5, 2011, and was prepared in parallel with the June 2011 estimate by Strathcona Mineral Services (“Strathcona”) recently completed on behalf of the Minera Juanicipio Joint Venture (“Joint Venture”) (see Press Release dated November 10, 2011). The Company continues to commission its own Mineral Resource estimates to ensure the integrity of the resource estimates published on behalf of the Joint Venture.

The Juanicipio property, located in the Fresnillo District, Zacatecas State, Mexico, is owned and operated by Minera Juanicipio S.A. de C.V., a Mexican incorporated joint venture company held 56% by Fresnillo plc and 44% by the Company. A National Instrument 43-101 technical report documenting the Mineral Resource estimate will be filed on SEDAR within 45 days.

Highlights of the August 2011 RPA Estimate

The August 2011 RPA estimate indicates more contained silver and gold as compared to the June 2011 estimate by Strathcona. The additional contained ounces are explained by RPA’s inclusion of several additional drill holes in the Juanicipio Vein, the addition of two extra zones (Stockwork and Hanging Wall Vein 1) and a different approach to the calculation of cut-off grade. The RPA estimate uses a cut-off of US$55.00/tonne Net Smelter Return (“NSR”), which includes contained values for silver, gold and base metals. The June 2011 Strathcona estimate uses 100 grams per tonne (g/t) contained silver as a cut-off grade. Both approaches are industry acceptable; however the use of the 100 g/t silver cut off used by Strathcona excludes a measurable volume of gold-bearing and base metal rich mineralization lying deeper in the vein system.

Indicated Mineral Resources are estimated by RPA to total 6.2 million tonnes of 728 g/t silver, 1.9 g/t gold, 1.9% lead, and 3.9% zinc at an NSR cut-off value of US$55.00 per tonne. Total contained metals in the Indicated Resource are 146 million ounces of silver, 384,000 ounces of gold, 267 million pounds of lead, and 539 million pounds of zinc.

Indicated Mineral Resources according to RPA are higher by 18 million ounces of silver and 38,000 ounces of gold as compared to the June 2011 Strathcona estimate.

At the same cut-off value of US$55.00 per tonne, Inferred Mineral Resources are estimated by RPA to total 7.1 million tonnes of 373 g/t silver, 1.6 g/t gold, 1.5% lead, and 2.6% zinc. The Inferred Resources are estimated to contain 85 million ounces of silver, 370,000 ounces of gold, 236 million pounds of lead, and 400 million pounds of zinc.

Inferred Mineral Resources according to RPA are higher by 14 million ounces of silver and 178,000 ounces of gold as compared to the June 2011 Strathcona estimate.

Notwithstanding the RPA estimate, MAG continues to support, as agreed to by the Joint Venture, the use and inclusion of the Strathcona estimate for the pending updated preliminary economic assessment being undertaken by AMC Mining Consultants (Canada) Ltd.

Dan MacInnis, President and CEO of MAG stated, “The RPA estimate with its additional ounces of silver and gold continues to validate that through ongoing drilling and discovery there remains considerable upside in the project area.”

The Indicated Mineral Resources are located in the Valdecañas Main Vein, the Hanging Wall Vein #1, and for the first time the Footwall Vein #1. The Inferred Mineral Resources are contained within the Valdecañas Main Vein, several hanging and footwall veins, a stock-work zone located within the Valdecañas structure and the Juanicipio Vein, located 1,100 metres to the south of the Valdecañas Vein.

Table 1 – August 5, 2011 RPA Estimate with June 1, 2011 Strathcona Resource Estimate for comparison