July 21

Osisko Intersects 114 Metres Averaging 2.04 g/t Gold at Barnat

Osisko Mining Corp. (TSX: OSK)(FRANKFURT: EWX) is pleased to announce new results from the definition drill program currently under way at South Barnat, a separate gold mineralized zone located approximately 1200 metres northeast of the center of the Canadian Malartic deposit. Significant new results include 2.04 g/t Au over 114.0 metres (BA08-3025) and 1.58 g/t Au over 104 metres (BA08-3026). Higher grade intercepts included 5.90 g/t Au over 27.4 metres in hole BA08-3031B. Results from eight new holes are tabled below:

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 Hole No.   Section  From (m)  To (m)  Length (m)  Au g/t
BA08-3017      500E     72.5   124.0        51.5     1.01
 And                   254.7   264.3         9.6     6.45
 including             263.0   264.3         1.3    37.30
 And                   283.7   298.4        14.7     2.20
BA08-3023      700E    131.0   223.0        92.0     2.46
 And                   239.5   319.0        79.5     0.79
BA08-3024      650E    125.7   146.4        20.7     2.66
BA08-3025      650E     69.0   183.0       114.0     2.04
 And                   208.5   247.5        39.0     0.52
BA08-3026      450E     23.0   127.0       104.0     1.58
 including              34.5    40.0         5.5     9.66
 including             124.0   127.0         3.0    12.42
 And                   281.0   334.0        53.0     1.00
BA08-3027      450E     16.5   100.1        83.6     1.34
BA08-3028      400E     56.0    90.0        34.0     2.62
 including              57.5    61.5         4.0    13.08
BA08-3031B     650E     27.9    55.3        27.4     5.90
 including              27.9    28.8         0.9    62.90
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The definition drill program is focused on an 850 metre-long grid oriented northwest-southeast with drill sections spaced 50 metres apart. All holes on this grid are inclined 40 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. Drill hole BA08-3030 did not intersect significant mineralization. Drill holes BA08-3024 and BA08-3031B did not reach the intended target depths, and the latter was lost in high grade mineralization. Selected holes are being re-drilled with larger diameter core (HQ) in order to augment recoveries and/or reach intended targets. Assay results from hole BA08-3029 and further holes at South Barnat are pending.

The new drill intersections and compilation of previous work suggest that the minimum strike length of the South Barnat Zone is 775 metres with a true width between 20 and 100 metres.

The mineralized zone is open to the northwest and southeast, and extends to a minimum depth of 250 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 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 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 $160 million on hand and is carrying out an aggressive definition drilling and exploration campaign.

An updated NI 43-101 compliant, measured and indicated resource estimate on the main Canadian Malartic gold deposit is scheduled for release in Q3 2008. This updated resource estimate will 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.

Contacts: Osisko Mining Corp. John Burzynski Vice-President Corporate Development 514-735-7131 www.osisko.com Osisko Mining Corp. Daniel Boase Investor Relations 416-742-5600 Toll Free: 1-866-580-8891

SOURCE: Osisko Mining Corporation

http://www.osisko.com