A pneumatic tire includes a tread portion provided with three to five circumferentially extending main grooves and a plurality of lateral grooves, to form a plurality of block rows each of which includes a plurality of tread blocks. Each tread block includes a ground contact surface with a polygonal shape that has at least five sides and each interior angle of not less than 90 degrees. Each ground contact surface of the tread block includes a maximum axial width W1 positioned between its circumferentially both ends, a circumferential length L1 between its circumferentially both ends, and a ratio W1/L1 of the maximum axial width W1 to the circumferential length L1 in a range of from 0.6 to 0.9.