To improve water evacuation property while preventing uneven wear, as well as to significantly improve the on-ice/snow performances by optimizing a tread pattern.This pneumatic tire has, in at least a part of a tread portion 1, a small block group GB, the small block group including a plurality of small blocks 3 arranged close together. The small block group GB comprises at least one circumferential main groove positioned 4 including see-through groove portion which linearly extends in the tread circumferential direction and at least one rib-like land portion 6 provided adjacently to the circumferential main groove and forming a groove side face 5 of the circumferential main groove 4 and continuously extending in the circumferential direction. A number density D of the small blocks is set within a range of 0.003 to 0.04 (pieces/mm2), the number density D representing the number of the small blocks per unit of an actual ground contact area of the small block group.