Osisko Pours First Gold at Canadian Malartic Mine

MONTREAL, QUEBEC -- (Marketwire) -- 04/13/11 -- Editors Note: A photo for this release is available via Marketwire's website.

Osisko Mining Corporation ('Osisko') (TSX: OSK)(FRANKFURT: EWX) is pleased to announce that today it has poured its first gold bar at its flagship Canadian Malartic Mine.

Mr. Sean Roosen, President and CEO, commenting on this major milestone said: 'We are extremely pleased to achieve our first gold production at Canadian Malartic, after only six years from drilling our first hole on the property. Commissioning has gone very smoothly, and we are well on track to achieve commercial production by the end of May. This achievement is a direct result of the outstanding efforts from Osisko's management team and employees, our contractors, suppliers, the residents of Malartic and officials from the government of Quebec. We also express our gratitude to our shareholders, bankers and lenders who have supported our vision of building a world class gold mining operation.'

About Osisko Mining Corporation

Osisko Mining Corporation is currently commissioning the Canadian Malartic Gold Mine, evaluating adjacent areas for a large-scale open pit, bulk-tonnage mining operation and pursuing exploration of the Hammond Reef Gold Project in Northern Ontario. The Company is well-funded with approximately $230 million on hand.

Forward-Looking Statements

Certain statements contained in this press release may be deemed 'forward-looking statements'. All statements in this release, other than statements of historical fact, that address events or developments that Osisko expects to occur, are forward looking statements. Forward looking statements are statements that are not historical facts and are generally, but not always, identified by the words 'expects', 'plans', 'anticipates', 'believes', 'intends', 'estimates', 'projects', 'potential', 'scheduled' and similar expressions, or that events or conditions 'will', 'would', 'may', 'could' or 'should' occur including, without limitation, the commencement of commercial production. Although Osisko believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, including, without limitation, that all technical, economical and financial conditions will be met in order to warrant further development of its projects and commercial production of its Canadian Malartic Mine, such statements are not guarantees of future performance and actual results may differ materially from those in forward looking statements. Factors that could cause the actual results to differ materially from those in forward-looking statements include gold prices, access to skilled consultants, mining development personnel, results of exploration and development activities, Osisko's limited experience with production and development stage mining operations, uninsured risks, regulatory changes, defects in title, availability of personnel, materials and equipment, timeliness of government approvals, actual performance of facilities, equipment and processes relative to specifications and expectations, unanticipated environmental impacts on operations market prices, continued availability of capital and financing and general economic, market or business conditions. These factors are discussed in greater detail in Osisko's most recent Annual Information Form and in the most recent Management Discussion and Analysis filed on SEDAR, which also provide additional general assumptions in connection with these statements. Osisko cautions that the foregoing list of important factors is not exhaustive. Investors and others who base themselves on forward-looking statements should carefully consider the above factors as well as the uncertainties they represent and the risk they entail. Osisko believes that the expectations reflected in those forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward-looking statements included in this press release should not be unduly relied upon. These statements speak only as of the date of this press release.

To view the photo associated with this press release, please visit the following link: http://www.marketwire.com/library/20110413-osk_800.jpg.

Contacts:

Osisko Mining Corporation

John Burzynski

Vice-President Corporate Development

416-363-8653


Osisko Mining Corporation

Sylvie Prud'homme

Investor Relations

514-735-7131

Toll Free: 1-888-674-7563
www.osisko.com