[1] Including topographic drilling of 4.9 million tonnes in 2013 and 2.5 million tonnes for the year 2012.

With the increased development achieved at Canadian Malartic in the past year, Osisko has seen enhanced operating flexibility with more working areas becoming available. In addition, on December 15, 2013 the mine completed its final blast over old surface crown pillars. Drilling and blasting procedures over these specific areas had required special attention to ensure the safety of the operating team, with associated higher mining cost. Special procedures are no longer required, and this will reduce costs and accelerate mining in the higher grade zones, as seen with record grades in December.

Mill throughput continued to improve towards the 55,000 tonnes per day nameplate capacity. Mill availabilities increased to 93.7% from 90.8% in 2012 and 86.0% in 2011. Gold recoveries were 88.9%, well above the 85.9% planned in the feasibility study.

With higher gold output, increased operating flexibility, and the initiation of optimization programs, costs are continuing to decline. It is anticipated that with further operating efficiencies and the weakening Canadian dollar, costs will continue to improve.

Cash and debt balances (unaudited)

With the strong performance of the Canadian Malartic mine, the Company was able to increase its cash balance during the year and to reduce debt.  The December 31, 2013 cash balance² was estimated at $210.5 million compared to $155.5 million in 2012.

During 2013 the Company improved its financial flexibility by rescheduling its debt payments. The outstanding debt at year-end is estimated as follows:

² Including cash and cash equivalents, short-term investments and restricted cash

NON-IFRS MEASURES OF PERFORMANCE

The Company has included a non-IFRS measure: “Cash costs per ounce”.

The Company believes that this measure, together with measures determined in accordance with IFRS, provide investors with an improved ability to evaluate the underlying performance of the Company. Non-IFRS measures do not have any standardized meaning prescribed under IFRS, and therefore they may not be comparable to similar measures employed by other companies. The data is intended to provide additional information and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with IFRS.

Cash costs per ounce

“Cash costs per ounce” is defined as the production costs of one ounce of gold excluding non-cash costs for a certain period. “Cash costs per ounce” is obtained from “Production costs” and “Royalties” less non-cash “Share-based compensation” and “By-product credits (silver sales)”, adjusted for “Production inventory variation” for the period, divided by the “Number of ounces of gold produced” for the period.

About Osisko Mining Corporation

Osisko Mining Corporation operates the Canadian Malartic Gold Mine in Malartic, Québec and is pursuing exploration on a number of properties in Ontario and Mexico.

Mr. Luc Lessard, Eng., Senior Vice-President and Chief Operating Officer of Osisko, is the Qualified Person who has reviewed this news release and is responsible for the technical information reported herein, including verification of the data disclosed.

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, accuracy of cash costs per ounce and cash balance estimates, that continued optimization at the mill will yield further increases in throughput, that anticipated increases in throughput and higher grade will generate another record year at Canadian Malartic, that costs will continue to improve as a result from further operating efficiencies and the weakening Canadian dollar. Although Osisko believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, including, without limitation, that all technical, economical, regulatory and financial conditions will be met in order to continue optimization at the mill to further increases in throughput, to access higher grade ore and to improve costs, 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.