OSISKO INTERSECTS 102 METRES AVERAGING 3.21 G/T Au AT SOUTH BARNAT

Montreal, December 3, 2008 - Osisko Mining Corporation (�Osisko�, OSK - TSX, EWX - Deutsche Boerse) is pleased to announce new results from the definition drill program currently under way at South Barnat, a separate gold mineralized zone located northeast of the Canadian Malartic deposit.  Significant results include 3.21 g/t Au over 102.0 metres (BA08-3154), 3.16 g/t Au over 54.0 metres (BA08-3149) and 1.78 g/t Au over 106.0 metres (BA08-3152).  Narrow zones of higher grade gold values were also encountered, including 51.0 g/t Au over 1.5 m (BA08-3149) and 17.4 g/t Au over 6.0 m (BA08-3154). Results from eighteen new holes are tabled below:

Drill holes BA08-3155 and BA08-3159 did not reach the intended target depths and did not intersect significant mineralization. Drill holes BA08-3146, BA08-3148, BA08-3152, BA08-3162 and BA08-3164 were lost in fault zones or intercepted historic mine workings and did not reach the intended target depths. Assay results for further holes at South Barnat are pending.  

The definition drill program is focused on an 850 metre-long grid oriented northwest-southeast with drill sections spaced 25 metres apart. All holes on this grid are inclined 45 to 75 degrees to the northeast or southwest. True widths of the mineralized intersections reported above are 40 to 70 percent of the drilled intersections.

Drilling to date suggests that the minimum strike length of the South Barnat Zone is 850 metres with a true width between 30 and 160 metres. The mineralized zone is open along strike to the southeast, where it merges with the old East Malartic M ine. It extends to depths of 250 to 400 metres in the southeastern portion, where the system is still open at depth. Estimated depth in the northwestern third of the deposit is 130 to 200 metres.

Mineralization in the South Barnat Zone is located to the north and south of the old Barnat and East Malartic mine workings, largely along the southern edge of the Cadillac fault. The gold mineralization comprises multiple subvertical, tabular subzones hosted both in silicified greywackes of the Pontiac Group south of the fault contact and in schistose, carbonated and biotitic ultramafic rocks north of the fault contact. Porphyry dykes on both sides of the fault contain disseminated mineralization as well as late quartz veins containing visible gold. Gold mineralization in the South Barnat Zone likely extends to the east along the north and south walls of the past-producing East Malartic mine.

All NQ or HQ core assays reported above were obtained by standard 50 g fire assaying-AA finish or gravimetric finish at ALS Chemex laboratories in Val d'Or, Quebec. Reported weighted averages were calculated using a minimum of 0.50 g/t Au over successive maximum intervals of 20 metres with no upper cut-off of individual assays.  Intersected drifts or lost core within mineralized intersections were incorporated as blank intervals.

Osisko Mining Corp. is currently evaluating the Canadian Malartic gold deposit and adjacent areas for a large-scale open pit, bulk-tonnage mining operation. The Company is well-funded with approximately $120 million on hand and is carrying out an aggressive definition drilling and exploration campaign. A NI 43-101 compliant Reserve/Resource estimate and Feasibility Study on the main Canadian Malartic gold deposit was released on November 25, 2008 and will be filed on SEDAR shortly. This estimate does not include the South Barnat Zone nor any other mineralized zone located outside the main deposit that is curren tly being evaluated by Osisko.

Mr. Robert Wares, P. Geo., Executive Vice-President and COO of Osisko, is the Qualified Person responsible for the technical information reported in this news release.
 
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 the Corporation 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.  Although the Corporation believes the expectations expressed in such forward-l ooking statements are based on reasonable assumptions, including, without limitation that all technical, economical and financial conditions will be met in order to put the Canadian Malartic Project into commercial production, 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 and mill production personnel, results of exploration and development activities, the Corporation�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 env ironmental 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 the Corporation�s most recent Annual Information Form filed on SEDAR, which also provides additional general assumptions in connection with these statements.  The Corporation cautions that the foregoing list of important factors is not exhaustive.  Investors and others who base themselves on the Corporation�s forward-looking statements should carefully consider the above factors as well as the uncertainties they represent and the risk they entail.  The Corporation 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.

For further information, please contact:

John Burzynski
Vice-President Corporate Development
Tel. (514) 735-7131
www.osisko.com

Daniel Boase
Investor Relations
Tel. (416) 742-5600
Toll Free: 1-866-580-8891

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