A pneumatic tire includes a tread portion provided with a pair of shoulder main grooves (3) adjacent to each tread edge and a pair of center main grooves (4) disposed axially inwardly of the shoulder main grooves to define a pair of middle portions (6) each of which is between the adjacent shoulder main groove and center main groove. The center main grooves have groove widths W2 larger than the groove widths W1 of the shoulder main grooves. The respective middle portions are provided with a plurality of inner middle lug grooves (21) extending axially outwardly of the tire from the center main groove, and a plurality of outer middle lug grooves (22) extending axially inwardly of the tire from the shoulder main groove. The total number of inner middle lug grooves is smaller than the total number of outer middle lug grooves in each middle portion.
