N@N

Osisko Mining Corporation: Osisko Intersects 3.19 g/t Au Over 76.5 Metres at South Barnat

MONTREAL, QUEBEC--(Marketwire - Nov. 27, 2008) - Osisko Mining Corporation ("Osisko")(TSX:OSK)(FRANKFURT:EWX) is pleased to provide new results as well as an update from the definition drill program currently under way on the South Barnat Zone, a separate gold mineralized system located approximately 1200 metres northeast of the center of the Canadian Malartic deposit.

New drill results from the current program include 3.19 g/t Au over 76.5 metres (BA08-3124), 1.62 g/t Au over 177.0 metres (BA08-3142) and 2.03 g/t Au over 131.8 metres (BA08-3143). Narrow higher-grade intervals include 15.4 g/t Au over 6.0 metres (BA08-3135).

The definition drill program is focused on an 850 metre-long grid oriented northwest-southeast with drill sections spaced 50 metres apart (Phase 14 of the Canadian Malartic drill program). All holes on this grid are inclined 45 to 75 degrees to the northeast or southwest. Phase 14 has now been completed with 228 drill holes totaling 50,200 metres, of which assay results have been processed and released for 145 holes, including new results in this press release. The weighted average grade of a total of 10,700 metres of mineralized intersections intersected to date is 1.91 g/t Au (calculated using an upper cut of 30 g/t Au and a minimum of 0.50 g/t Au over successive maximum intervals of 20 metres).

Phase 15 is underway with infill drilling on remaining sections spaced 25 metres apart. Approximately 45,000 metres of this phase have been drilled to date, from a total drill program estimated at 120,000 metres and expected to be completed by the end of January 2009.

Wireframe modeling of the deposit and of underground voids will begin next week with the objective of releasing an inferred resource estimate by the end of January 2009. With the completion and integration of the Phase 15 drilling, the Company plans on completing a measured and indicated resource estimate by Q2 2009.

Results from twenty-two new holes are tabled below:

---------------------------------------------------------------------------
Hole No. Section From (m) To (m) Length (m) Au g/t
---------------------------------------------------------------------------
BA08-3121 350E 43.2 78.3 35.1 1.85
---------------------------------------------------------------------------
BA08-3122 350E 23.0 47.3 24.3 1.54
 And 68.0 89.0 21.0 4.09
 including 69.5 71.3 1.8 23.70
---------------------------------------------------------------------------
BA08-3123 350E 266.1 296.6 30.5 1.00
---------------------------------------------------------------------------
BA08-3124 350E 155.5 232.0 76.5 3.19
 including 176.0 177.5 1.5 23.00
 And 264.5 316.0 51.5 1.70
---------------------------------------------------------------------------
BA08-3125 300E 0.8 95.5 94.7 0.92
---------------------------------------------------------------------------
BA08-3126 600E 36.0 236.5 200.5 1.26
 including 42.5 44.0 1.5 30.10
 And 272.5 423.0 150.5 0.85
---------------------------------------------------------------------------
BA08-3127 350E 6.0 92.7 86.7 0.93
 And 122.5 157.0 34.5 1.83
---------------------------------------------------------------------------
BA08-3128 250E 15.6 74.5 58.9 1.93
---------------------------------------------------------------------------
BA08-3129 250E 15.0 48.0 33.0 2.72
 including 25.5 27.0 1.5 38.90
---------------------------------------------------------------------------
BA08-3130 250E 15.3 114.5 99.2 1.49
 including 75.0 76.0 1.0 27.30
---------------------------------------------------------------------------
BA08-3133 400E 22.7 71.5 48.8 5.78
 including 53.5 55.0 1.5 97.70
---------------------------------------------------------------------------
BA08-3134 525E 21.0 81.0 60.0 1.78
---------------------------------------------------------------------------
BA08-3135 525E 24.5 72.3 47.8 3.50
 including 45.0 51.0 6.0 15.4
---------------------------------------------------------------------------
BA08-3136 525E 38.5 70.4 31.9 2.84
---------------------------------------------------------------------------
BA08-3138 450E 79.0 99.0 20.0 1.31
---------------------------------------------------------------------------
BA08-3139 450E 45.9 73.0 27.1 1.70
 And 194.5 286.0 91.5 1.08
---------------------------------------------------------------------------
BA08-3140 700E 194.5 223.0 28.5 1.70
---------------------------------------------------------------------------
BA08-3141 700E 205.0 268.0 63.0 4.64
 including 253.0 254.5 1.5 99.10
---------------------------------------------------------------------------
BA08-3142 700E 175.0 352.0 177.0 1.62
---------------------------------------------------------------------------
BA08-3143 500E 60.0 191.8 131.8 2.03
---------------------------------------------------------------------------
BA08-3144 500E 12.7 96.0 83.3 0.89
 And 128.5 218.1 89.6 1.90
 including 132.5 134.0 1.5 25.50
---------------------------------------------------------------------------
BA08-3145 500E 70.0 97.8 27.8 1.70
 And 163.8 211.9 48.1 1.18
 And 266.5 282.5 16.0 1.47
---------------------------------------------------------------------------

Drill holes BA08-3131, BA08-3132 and BA08-3137 did not reach their intended targets and did not intersect significant mineralization. Drill holes BA08-3122, BA08-3125, BA08-3134, BA08-3135, BA08-3136 intercepted historic mine workings and did not reach the intended target depths.

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. Assay results for further holes at South Barnat are pending.

Drilling to date suggests that the minimum strike length of the South Barnat Zone is 850 metres with a true width between 20 and 160 metres. The mineralized zone is open along strike to the southeast, where it merges with the old East Malartic Mine. 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 in the table 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 $130 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 September 25, 2008 and will be filed on SEDAR shortly. This estimate did not include the South Barnat Zone nor any other mineralized zone located outside the main deposit that is currently being evaluated by Osisko.

Mr. Robert Wares, P. Geo. and Executive Vice-President 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-looking 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 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 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.