Field studies were carried out under non-cropped situations using tank mix applications of some herbicides against Canada thistle (Cirsium arvense) during 2007-08 and 2008-09. Tank mix applications of carfentrazone 20 g/ha with glyphosate 1.0% (0.75% repeat year) plus 0.25% non-ionic surfactant (NIS) provided 95 (95) and 87% (82) control of Canada thistle compared to 95 (97) and 83% (82) control by glyphosate alone at 2.0+0.25% NIS, 8 and 13 weeks after treatment (WAT), respectively. Carfentrazone alone was not effective. In another experiment, tank mix applications of carfentrazone 20 g/ha+glyphosate 0.75+0.25% NIS+2,4-D amine 500 g/ha provided 98, 99, 96 and 89% control of Canada thistle compared to 85, 95, 92 and 79% control by tank mixing of 2,4-D 500 g/ha+glyphosate 1.0+0.25% NIS and 89, 92, 88 and 78% control by glyphosate alone 2.0+0.25% NIS, respectively, at 21, 42, 56 and 75 DAT. The mortality of Canada thistle was similar when glyphosate 1.0 or 1.5% was tank mixed with 20 or 40 g/ha of carfentrazone. Effect of 2, 4-D amine was significantly lower when used alone or tank mixed with carfentrazone compared to their mixture with glyphosate. The effect of herbicides was significantly higher in the second year compared to first year of spraying. Tribenuron alone at 25 g/ha+0.25% NIS or its tank mixture at 20 g/ha with 2,4-D ester 250 g/ha, metsulfuron 4 g/ha or carfentrazone 20 g/ha was not effective against Canada thistle. Similarly, tank mix applications of metsulfuron 2 or 4 g/ha with 2,4-D 250 or 500 g/ha failed to satisfactorily control Canada thistle. Glyphosate 1.0% alone or with metsulfuron 4 g/ha provided similar control of Canada thistle, but effect was significantly lower than alone application of glyphosate at 2.0+0.25% NIS