Osisko Investor Day Thursday March 20

Canadian Malartic Updated Mine Plan to be Released

MONTREAL, QUEBEC--(Marketwired - Mar 18, 2014) - Osisko Mining Corp. (TSX:OSK)(FRANKFURT:EWX) ("Osisko") cordially invites analysts and investors to attend Osisko's "Investor Day" presentation and luncheon, this Thursday, March 20^th at 12:00pm, to be held at the Trump Hotel, downtown Toronto. Osisko's senior management and technical staff will be present for a comprehensive discussion of the recently released reserve update (see Osisko press release dated March 12, 2014) and the updated mine plan for Canadian Malartic (to be released Thursday morning pre-market open followed by a 9:00am conference call). Those planning to attend are asked to R.S.V.P. at (416) 363-8653 prior to 5pm, March 19.

Updated Mine Plan Conference Call Information

Osisko will host a conference call on Thursday, March 20, 2014 at 9:00 EDT, where senior management will discuss the updated mine plan and provide an update of the Company's activities. Those interested in participating in the conference call should dial in approximately five to ten minutes before the start of the conference to allow ample time to access at 1-416-981-9000 (Toronto local and international), or 1-800-893-0176 (North American toll free). An operator will direct participants to the call.

The conference call replay will be available from 11:00 EDT on March 20, 2014 until 23:59 EDT on April 3, 2014 with the following dial in number: 1 416 626 4100 or toll-free 800 558 5253, access code 21711924.

Reject the Inadequate Goldcorp Offer

As previously disclosed, the Osisko Board of Directors has unanimously recommended that Osisko shareholders reject the hostile take-over bid initiated by Goldcorp and not tender their Osisko shares to the Goldcorp offer. The Osisko Board determined that the Goldcorp offer fails to adequately compensate Osisko shareholders for, among others things, the strategic value of Osisko's world-class asset base, the significant upside potential of Osisko's Canadian Malartic Mine, or the increased risk inherent in Goldcorp common shares. The full basis for the Osisko Board's recommendation is available in a Directors' Circular, a copy of which is available online at www.osisko.com.

Shareholders who have questions or who may have already tendered their shares to the Goldcorp Offer and wish to withdraw them, may do so by contacting our Information Agent, Laurel Hill Advisory Group at:

North American Toll Free: 1-877-452-7184

Banks, Brokers or collect calls: 416-304-2011

Email: assistance@laurelhill.com