A pneumatic tire 10 in which a plurality of circumferential main grooves 11 that extend in the tire circumferential direction are formed in a tread surface portion, and a plurality of land portion rows 14 are partitioned by the circumferential main grooves 11, in which in at least one of the plurality of the land portion rows 14 a circumferential auxiliary groove 15 extending in the tire circumferential direction and having a narrower width and shallower depth than those of the circumferential main grooves 11 is formed in a position avoiding the tire centerline CL, and among both side faces 15a and 15b defining the circumferential auxiliary groove 15, one side face on the tire centerline side extends along the normal direction of the tread surface portion or is inclined to the tire centerline side by 5° or less with respect to the normal direction, and the other side face on the side opposite to the tire centerline side is inclined to the side opposite to the tire centerline side by 10° to 30° with respect to the normal direction. In accordance with the present invention, it is possible to improve the turning performance on snowy roads without decreasing the steering stability or quietness during travel on a dry road surface.