Osisko Reports Significant New Intersections at Barnat Extension, Including 3.19 g/t Au Over 142 Metres

MONTREAL, QUEBEC--(Marketwire - Jan. 25, 2011) - Osisko Mining Corporation ("Osisko") (TSX:OSK)(FRANKFURT:EWX) is pleased to announce additional results from the 2010 definition drill program on the Barnat Extension, located on Osisko's 100%-owned Canadian Malartic gold property, within and immediately to the east end of the current engineered pit of the Canadian Malartic and Barnat deposits. The 115 hole, 25,100 metre definition drilling program was executed along 25 metre-spaced sections and was completed in the fall of 2010.

Results for thirty-six new holes, mainly from the Barnat Extension program (east of section 5800E) are presented below. Highlights include 142.6 metres averaging 3.19 g/t Au (BA10-3913 uncut), 121.2 metres averaging 2.78 g/t Au (BA10-3911 uncut), and 142.7 metres averaging 1.40 g/t Au (BA10-3914).

Assay data from these holes are not included in the current resource block model, and in the majority of cases represent new mineralization and new ounces hosted within Pontiac metasediments. Mineralized intersections between sections 5675E and 6150E are partially outside (below) the existing engineering pit and therefore not included in current reserves. All holes to the east of section 6150E are completely outside the current engineered pit. Out-of-pit intersections are indicated below by asterisks:

Hole No.	Section	Az./dip	From (m)	To (m)	Length	Au g/t	Au g/t
					(m)	(uncut)	(cut)
BA10-3893B	6075E	180/60	24.0	52.5	28.5	3.63	---
including			40.5	42.0	1.5	19.35	---
BA10-3896	6075E	0/44	43.5	154.0	110.5	1.42	---
including
BA10-3898	6075E	0/60	102.5	120.5	18.0	0.82	---
And**			155.0	224.0	69.0	2.04	---
BA10-3902	6050E	0/45	60.0	82.3	22.3	1.25	---
And			163.5	198.4	34.9	1.05	---
BA10-3903	6050E	3/60	30.0	59.0	29.0	1.49	---
BA10-3904	6050E	180/45	15.0	18.0	3.0	7.25	---
And			79.1	88.5	9.4	2.06	---

BA10-3905	6075E	180/45	75.1	100.5	25.4	1.43	---
And**			126.0	139.5	13.5	1.70	---
BA10-3906	6100E	180/45	71.6	136.6	65.0	1.25	---
BA10-3907	6025E	0/45	24.0	39.0	15.0	2.11	---
And			162.0	219.7	57.7	1.02	---
And**			247.8	269.4	21.6	0.87	---
BA10-3908	6025E	0/54	18.0	49.5	31.5	1.88	---
And			143.5	169.0	25.5	0.97	---
And**			186.5	256.5	70.0	1.52	---
BA10-3909**	6125E	180/50	63.0	115.5	52.5	1.84	---
And**			136.1	180.0	43.9	0.91	---
BA10-3910**	6150E	180/48	24.5	117.5	93.0	1.69	---
And**			144.0	179.5	35.5	1.01	---
BA10-3911**	6150E	180/64	41.6	162.8	121.2	2.78	2.27
including			52.5	54.0	1.5	71.30	30.00
BA10-3912	6000E	0/45	134.0	259.0	125.0	1.29	---
including			255.5	256.6	1.1	15.45	---
BA10-3913	6000E	0/53	12.5	15.0	2.5	4.92	---
And			169.5	210.0	40.5	1.25	---
And**			210.0	312.1	102.1	3.96	2.59
including			243.0	243.4	0.4	40.30	30.00
including			249.0	251.3	2.3	79.46	20.94
including			255.0	256.4	1.4	27.00
overall			169.5	312.1	142.6	3.19	2.21
BA10-3914**	6175E	180/45	70.3	213.0	142.7	1.40	---
including			158.0	159.5	1.5	11.05	---
BA10-3915	6175E	180/60	45.0	49.5	4.5	4.50	---
And**			87.4	205.5	118.1	1.07	---
BA10-3916	5975E	0/45	147.0	227.3	80.3	1.07	---
And**			246.5	286.5	40.0	0.97	---

BA10-3917**	5975E	0/52	217.1	238.0	20.9	2.27	---
BA10-3918**	6225E	180/57	95.5	139.5	44.0	1.63	---
BA10-3919**	6175E	180/45	43.0	95.5	52.5	1.60	---
And**			144.5	203.0	58.5	0.83	---
BA10-3920	5950E	0/46	195.0	276.2	81.2	1.87	---
including			272.2	273.4	1.2	23.90
BA10-3921	5950E	0/54	63.0	73.5	10.5	3.28	---
BA10-3922	5850E	180/56	159.5	170.5	11.0	1.00	---
And			221.2	233.1	11.9	1.01	---
BA10-3923	5825E	180/46	191.5	257.5	66.0	1.20	---
BA10-3924B**	5825E	180/53	276.0	277.7	1.70	39.50	30.00
And**			300.0	318.0	18.0	3.60	---
BA10-3925	5925E	0/47	202.6	262.0	59.4	0.96	---
BA10-3926**	5925E	0/56	231.0	244.0	13.0	1.25	---
And			275.0	279.4	4.4	2.67	---
BA10-3928**	5675E	215/52	202.5	233.5	31.0	0.53	---
BA10-3933	5700E	219/45	110.6	123.0	12.4	0.80	---
And			204.6	371.5	166.9	0.94	---

Drill holes BA10-3927, BA10-3929 to BA10-3932 and BA10-3934 did not intersect notable mineralization. The drill data suggest the Barnat Extension comprises two mineralized zones that parallel the southern limit of the Cadillac fault. The northerly extension (Sheehan Zone) is located within the Cadillac Fault and is hosted mostly by mineralized porphyry within sheared and altered ultramafic rocks. This zone is subvertical and is approximately 12 metres true thickness on average (range of 2 to 28 metres) and has been traced for at least 125 metres. The southerly extension (Mammoth Zone) is located in the Pontiac metasediments, approximately 35 metres south of the Sheehan Zone. This zone is comprised of silicified porphyry and metasediments similar to those of the Canadian Malartic deposit.

The Mammoth Zone dips subvertically to the north near surface and reverses to a 75 degree dip to the south at depth. Its average true thickness is approximately 40 metres (range of 25 to 60 metres). The thicker portions were intersected by drill holes BA10-3911 to BA10-3915. The Mammoth zone has now been traced along a strike length of 300 metres in the immediate area of the old East Malartic mine workings, and both zones are open to the east and at depth.

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 drill core weighted averages were calculated using a minimum of 0.34g/t Au over successive intervals of 20 metres. The reported lengths of isolated mineralized intervals were minimized, and an upper cut-off of 30 g/t Au was applied to individual assays where indicated. Intersected drifts or lost core within mineralized intersections were incorporated as blank intervals.

Osisko follows strict QA-QC protocol measures in keeping with industry standards and regulatory reporting requirements. Mr. Robert Wares, P. Geo. and Executive Vice-President of Osisko, and Mr. François Bouchard, P. Geo., are the Qualified Persons who has reviewed this news release and are responsible for the technical information reported herein, including verification of the data disclosed including the sampling, analytical and test data underlying the technical information.

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, the commencement of commercial production. Although Osisko 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 warrant further development of the project, 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.