TORONTO, ONTARIO–(EMWNews – Aug. 5, 2008) – Sierra Minerals Inc. (TSX:SIM) (“Sierra” or the “Company”) is pleased to announce the appointment of Ms. Rebecca Hudson as Chief Financial Officer of the Company. Ms. Hudson will be based at the Company’s head office in Toronto.

Ms. Hudson was most recently Controller of Zacoro Metals Corp. (“Zacoro”). Zacoro is a widely held Toronto-based mining company, with exploration and development projects in Mexico. In addition to assuming responsibility for financial reporting and internal controls, Ms. Hudson managed all local Mexican financial, tax and legal matters working through Mexican accounting and law firms. Prior to this, Ms. Hudson spent two years with Xstrata Canada (formerly Falconbridge Limited), as Manager, Financial Reporting and Control. She played a key role in the implementation of Sarbanes-Oxley regulations. Ms. Hudson has also recently provided consulting services to IAMGOLD Corporation and Argenta Oil and Gas.

Ms. Hudson holds a Bachelor of Arts with a concentration in accounting and a Masters of Accounting with a concentration in taxation from the University of Waterloo. She earned her C.A. designation in 2000 with Grant Thornton LP, followed by two years with PricewaterhouseCoopers LLP in the Dominican Republic. Ms. Hudson is fluent in both English and Spanish.

“We are extremely pleased to welcome Rebecca to the new Sierra team. I believe that her strengths in financial reporting and control coupled with her background in mining, specific knowledge of operating in Mexico and the ability to work seamlessly in both English and Spanish, will be invaluable as we strengthen our financial controls and grow the Company,” stated Michael Farrant, President and CEO of Sierra. “The addition of Rebecca rounds out our new management team following the recent announcement of Phil Davies as Chief Operating Officer (see press release dated July 9, 2008). I am confident that we now have the people in place to execute our plans and look forward to working with them both.”

New Head Office Address

The Company also wishes to announce that it has moved its Toronto head office as follows:

SIERRA MINERALS INC.
8 King Street East, Suite 810
Toronto, ON M5C 1B5
Tel: (416) 366-8211
Fax: (416) 366-7596

About Sierra Minerals

Sierra Minerals Inc. (TSX:SIM) is a Canadian based gold production and exploration company. Through its Mexican subsidiary, it owns 100% of the Cerro Colorado Gold Mine in Sonora, Mexico. The Company is currently completing its initial NI 43-101 mineral resource estimate on the property and plans to increase annualized production from 20,000 to 30,000 ounces of gold. In addition, the Company is exploring its extensive regional land package in Mexico which covers over 30,000 hectares. Further information about Sierra Minerals and the Cerro Colorado Gold Mine can be found on the Company’s website at www.sierraminerals.ca.

FORWARD-LOOKING STATEMENTS

This news release includes “forward-looking information”, as such term is defined in applicable securities laws. The forward-looking information includes, without limitation, the success of exploration activities and other similar statements concerning anticipated future events, conditions or results that are not historical facts including the extent of future production from the Cerro Colorado Gold Mine. These statements reflect management’s current estimates, beliefs, intentions and expectations; they are not guarantees of future performance. The Company cautions that all forward looking information is inherently uncertain and that actual performance may be affected by a number of material factors, many of which are beyond the Company’s control. Such factors include, among others, risks and uncertainties relating to exploration and development; the ability of the Company to obtain additional financing; the Company’s limited operating history; the need to comply with environmental and governmental regulations; political and economic instability and general civil unrest in Mexico, if any; potential defects in title to the Company’s properties; fluctuations in currency exchange rates; fluctuating prices of commodities; operating hazards and risks; competition; and other risks and uncertainties, including those described in the Company’s other regulatory filings filed with the Canadian Securities Administrators and available at www.sedar.com. Accordingly, actual future events, conditions and results may differ materially from the estimates, beliefs, intentions and expectations expressed or implied in the forward-looking information. All statements are made as of the date of this news release and the Company is under no obligation to update or alter any forward-looking information.