Osisko Mining Corporation

Proven and Probable Mineral Reserves

Property

Location

Osisko Interest

Cut-off

Proven

Probable

Proven and Probable

Tonnes

Grade

Au oz

Tonnes

Grade

Au oz

Tonnes

Grade

Au oz

g/t

(M)

g/t

(M)

(M)

g/t

(M)

(M)

g/t

(M)

Canadian Malartic

Quebec

100%

0.34

28.4

0.92

0.84

217.4

1.16

8.13

245.8

1.13

8.97

Mineral Resources (Indicated and Inferred)(excludes Proven and Probable reserves)

Property	Location	Osisko Interest	Cut-off	Indicated			Inferred
				Tonnes	Grade	Au oz	Tonnes	Grade	Au oz
			g/t	(M)	g/t	(M)	(M)	g/t	(M)
Canadian Malartic	Quebec	100%	0.34	70.4	0.99	2.23	20.0	0.73	0.47
Hammond Reef	Ontario	77.3%	0.3				259.4	0.80	6.70
Total						2.23			7.17

Note: Gold price used was US$825/oz

Canadian Malartic Project

Resource Estimates By Cut-Off Within US$825 Whittle Pit Shell

Indicated			Inferred				Total M&I
Grade (g/t)	Tonnes (M)	Oz (M)	Grade (g/t)	Tonnes (M)	Oz (M)	Cut-off (g/t)	Grade (g/t)	Tonnes (M)	Oz (M)
0.97	27.5	0.86	1.23	210.6	8.31	0.34	1.20	238.1	9.17
1.13	21.4	0.78	1.40	174.2	7.82	0.50	1.37	195.6	8.60
1.25	17.6	0.71	1.51	154.3	7.47	0.60	1.48	172.0	8.18
1.38	14.5	0.65	1.61	138.0	7.13	0.70	1.59	152.6	7.78
1.50	12.2	0.59	1.70	125.3	6.83	0.80	1.68	137.5	7.42
1.62	10.3	0.54	1.78	114.1	6.52	0.90	1.77	124.5	7.06
1.75	8.7	0.49	1.86	104.4	6.23	1.00	1.85	113.1	6.72

Inferred
Grade (g/t)	Tonnes (M)	Oz (M)	Cut-off (g/t)
0.90	3.8	0.11	0.34
1.05	2.9	0.10	0.50
1.18	2.3	0.09	0.60
1.31	1.8	0.08	0.70
1.42	1.6	0.07	0.80
1.55	1.3	0.06	0.90
1.67	1.1	0.06	1.00

Sensitivity of the In-Pit M&I Resource to Gold Price(Inferred excluded)

Gold Price (US$)	Grade (g/t)	Tonnes (M)	Oz (M)g/t	Strip Ratio (Waste/Ore)
$700	1.31	195.8	8.25	2.01
$825	1.20	238.1	9.17	1.91
$900	1.15	255.8	9.48	1.84
$1000	1.09	287.8	10.07	1.81
$1100	1.05	308.0	10.37	1.76

Hammond Reef Project

Mineral Resources By Cut-Off

Inferred
Grade (g/t)	Tonnes (M)	Oz (M)	Cut-off (g/t)
1.46	60.2	2.83	1.00
1.35	77.1	3.34	0.90
1.24	98.4	3.93	0.80
1.14	124.6	4.56	0.70
1.04	155.0	5.19	0.60
0.95	188.5	5.78	0.50
0.87	227.0	6.34	0.40
0.80	259.4	6.70	0.30
0.76	281.9	6.89	0.20

Technical Information

All Mineral Reserves and Mineral Resources have been calculated in compliance with the standards of the National Instrument 43-101.

For further details on the Mineral Reserves and Resources please refer to: Osisko’s press releases dated November 25, 2008 and February 10, 2010; Brett’s press releases of November 12, 2009, July 23, 2009 and October 15, 2008; Technical Reports “Updated resource and reserve estimates for the Canadian Malartic Project, March 22, 2010” and Preliminary Assessment of the Hammond Reef Gold Project Atikokan, Ontario,Canada, November 27, 2009.

The technical information has been prepared under the supervision of, and reviewed by, the following Qualified Persons as defined by the Instrument 43-101:

• Mr. Terry Hennessey , P. Geo. of Micon International Limited, Mr. Elzéar Belzile, P. Eng. of BSI, Mr. Louis-Pierre Gignac, P. Eng. of G Mining Services Inc., and Mr. Robert Wares, P. Geo. and Executive Vice-President of Osisko for the Canadian Malartic Deposit.
• Mr. Joseph P. Ringwald, P. Eng., Vice-President Operations for Brett, Mr. John Zbeetnoff, P. Geo, Hammond Reef Project Manager for Brett, and Mr. Richard J. Lambert, P.E., Scott Wilson Roscoe Postle Associates, Inc. for the Hammond Reef Deposit.