Mainstream Minerals Corporation : appoints Lisa McCormack as Corporate Secretary

For Immediate Release

Winnipeg, MB - March 22nd, 2012

Mainstream Minerals Corporation (TSX.V: MJO) ("Mainstream" or the "Company") is pleased to announce the appointment of Lisa McCormack as Corporate Secretary of the Company subject to TSX Venture Exchange approval. Ms. McCormack is a seasoned professional law clerk, specializing in securities and corporate law. She is currently Corporate Secretary of several public companies including Trelawney Mining and Exploration Inc. Ms. McCormack has over 15 years of experience working for various securities and corporate finance law firms in Toronto and assisting public issuers within the mining industry.

About Mainstream Minerals

Mainstream Minerals Corporation is a mineral exploration and development company focused on precious metal mining properties with economic potential, with the aim of possibly bringing such properties to commercial production. With a portfolio of six projects located in the Birch-Uchi Greenstone Belt, Red Lake Mining District, the company is well positioned to take advantage of the resurgence of exploration and development activities in this prospective belt located 80 kilometres due east of the main Red Lake Greenstone Belt.

These six projects cover an area of approximately 28,600 acres and host several known gold occurrences and past producing mines. Other projects include the Rowan Lake Project on the Cameron Lake-Pipestone Fault in the Kenora Mining District, the West Keefer Claims located in the West Timmins area in north-central Ontario and the Casa Berardi Claims in northern Québec.

MJO Shares Outstanding: 54,522,130

ON BEHALF OF THE BOARD

Signed "Michael Romanik"
Michael Romanik, President & CEO
[phone]
[e-mail]
www.mainstreamminerals.com

This news release includes certain forward-looking statements concerning the future performance of Mainstream Mineral Corporation's business, its operations and its financial performance and condition, as well as management's objectives, strategies, beliefs and intentions. The Company does not intend, and does not assume any obligation, to update these forward-looking statements. Forward-looking statements are frequently identified by such words as "may", "plan", "expect", "anticipate", "estimate", "intend" and similar words referring to future events and results. These forward-looking statements represent management's best judgment based on current facts and assumptions that management considers reasonable. The Company makes no representation that reasonable business people in possession of the same information would reach the same conclusions. All forward-looking information is inherently uncertain and subject to a variety of assumptions, risks and uncertainties, including the speculative nature of mineral exploration and development, fluctuating commodity prices, competitive risks and the availability of financing and as described in more detail in the Company's recent securities filings available at www.sedar.com. Actual events or results may differ materially from those projected in the forward looking-statements and readers are cautioned against placing undue reliance thereon.