Mainstream Minerals Corporation : announces board changes as a result of the Annual General and Special Meeting of Shareholders of October 25th, 2012

Winnipeg, Manitoba - October 31th, 2012

Mainstream Minerals Corporation (TSX.V: MJO)is pleased to announce the results from the Annual General and Special Meeting of Shareholders as was recently held in Winnipeg, Manitoba on October 25th, 2012. At the meeting, shareholders approved all of the resolutions put before them by management, including: (i) the election of all director nominees, (ii) the appointment of the auditors for the ensuing year and authorizing the directors to fix the auditors' remuneration, (iii) the approval of the comparative audited financial statements for the fiscal years ended November 30th, 2011 and 2010, and (iv) the approval by a majority of the disinterested shareholders of the Stock Option Plan as originally was approved by the directors of the company on June 11th, 2007.

Election of Directors

Mainstream Minerals Corporation's Board of Directors now consists of Gregory Gibson, Steven McIntyre, Dave Reid, James Darcel and Michael Romanik. Brief biographies of the new directors are as follows:

Gregory Gibson

Mr. Gibson was the President and Chief Executive Officer of Trelawney Mining and Exploration Inc. Under Mr. Gibson's leadership, Trelawney discovered and advanced the multi-million ounce Côté Lake gold deposit in Northern Ontario and then successfully negotiated the sale of Trelawney to Iamgold Corp. for $585-million. Mr. Gibson has over 30 years of experience in the mining industry as a mine manager for gold and copper mines in Australia, a nickel mine in Timmins, Ontario, and a gold mine in British Columbia. Previously he worked for JS Redpath, Dynatec Mining Ltd., Yilgarn Star Gold Mine and Copper Mines of Tasmania in a variety of operational capacities. He is presently a director of several junior mining companies.

Steven McIntyre

Mr. McIntyre has more than 30 years experience in the mining and mineral exploration business, including over 10 years with Noranda Mines Ltd. and 20 years as an officer and director of junior mineral exploration companies, including Dumont Nickel Inc., Northwest Explorations Inc., Timmins Nickel Inc. and Vedron Gold Inc., and more recently, as the Chairman and as a director of Trelawney Mining and Exploration Inc.

Dave Reid

Mr. Reid was the Vice President of Business Development and Investor Relations for Trelawney Mining and Exploration Inc. Mr. Reid is the former President and Chief Executive Officer of a private transportation company and has 30 years of business experience with fleet and maintenance operations as well as 10 years' experience in underground mechanical maintenance.

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: 65,102,130

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.