A pneumatic tire having a specified installing direction to a vehicle, which comprises: a tread portion having an inboard tread edge and an outboard tread edge; a pair of circumferentially extending inboard and outboard center main grooves (3B, 3A) disposed both sides of a tire equator to define a center portion therebetween; a pair of circumferentially extending inboard and outboard shoulder main grooves (4B, 4A) disposed axially outside of the inboard and outboard center main grooves (3B, 3A); a pair of middle portions (7A, 7B) which include an inboard middle portion defined between the inboard center main groove and the inboard shoulder main groove and an outboard middle portion defined between the outboard center main groove and the outboard shoulder main groove; a pair of shoulder portions (8A, 8B) which include an inboard shoulder portion defined the axially outside of the inboard shoulder main groove and an outboard shoulder portion defined the axially outside of the outboard shoulder main groove; the outboard shoulder main groove having a groove width (W1c) smaller than those (W1d, W1b) of the inboard shoulder main groove and center main grooves; and a plurality of outboard shoulder lateral grooves each of which extends from the outboard tread edge toward the tire equator beyond the outboard shoulder main groove so as to have axially inner end on the outboard middle portion; characterized in that the outboard middle portion having a width (W3b) larger than that of the inboard middle portion; a plurality of outboard middle lateral grooves each of which has an outboard end on the outboard middle portion and an inboard end on the center portion; each said inner end of the outboard shoulder lateral groove provided in different position in the circumferential direction of the tire with respect to each said outboard end of the outboard middle lateral groove; and a plurality of outboard middle narrow grooves each of which has a groove width smaller than those of said lateral grooves (5A, 5B) and connects between the inner end of the outboard shoulder lateral groove and the outboard end of the outboard middle lateral groove. a tread portion having an inboard tread edge and an outboard tread edge; a pair of circumferentially extending inboard and outboard center main grooves (3B, 3A) disposed both sides of a tire equator to define a center portion therebetween; a pair of circumferentially extending inboard and outboard shoulder main grooves (4B, 4A) disposed axially outside of the inboard and outboard center main grooves (3B, 3A); a pair of middle portions (7A, 7B) which include an inboard middle portion defined between the inboard center main groove and the inboard shoulder main groove and an outboard middle portion defined between the outboard center main groove and the outboard shoulder main groove; a pair of shoulder portions (8A, 8B) which include an inboard shoulder portion defined the axially outside of the inboard shoulder main groove and an outboard shoulder portion defined the axially outside of the outboard shoulder main groove; the outboard shoulder main groove having a groove width (W1c) smaller than those (W1d, W1b) of the inboard shoulder main groove and center main grooves; and a plurality of outboard shoulder lateral grooves each of which extends from the outboard tread edge toward the tire equator beyond the outboard shoulder main groove so as to have axially inner end on the outboard middle portion; characterized in that the outboard middle portion having a width (W3b) larger than that of the inboard middle portion; a plurality of outboard middle lateral grooves each of which has an outboard end on the outboard middle portion and an inboard end on the center portion; each said inner end of the outboard shoulder lateral groove provided in different position in the circumferential direction of the tire with respect to each said outboard end of the outboard middle lateral groove; and a plurality of outboard middle narrow grooves each of which has a groove width smaller than those of said lateral grooves (5A, 5B) and connects between the inner end of the outboard shoulder lateral groove and the outboard end of the outboard middle lateral groove.