A pneumatic tire having a designated installing direction to a vehicle, comprising a tread portion having an inboard tread edge and an outboard tread edge, the tread portion being provided with: a pair of circumferentially extending inboard and outboard center main grooves (3A, 3B) disposed both sides of a tire equator (c) to define a center portion therebetween; a pair of circumferentially extending inboard and outboard shoulder main grooves (3C, 3D) disposed axially outside of the inboard and outboard center main grooves (3A, 3B); a pair of middle portions (4B, 4C) 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; and a pair of shoulder portions (4D, 4E) 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, wherein each of the inboard center main groove, the outboard center main groove and the inboard shoulder main groove has a groove width (W1a, W1b, W1c) in a range of from 10 to 20 mm, the outboard shoulder main groove has a groove width (W1d) in a range of from 2 to 5 mm, the outboard shoulder portion is provided with a plurality of outboard shoulder lateral grooves each of which extends at least from the outboard tread edge to the axially inside of the tire and terminates without reaching the outboard shoulder main groove, the inboard shoulder portion is provided with a plurality of inboard shoulder lateral grooves each of which connects between the inboard tread edge and the inboard shoulder main groove, characterized in that the outboard middle portion is provided with a plurality of outboard middle lateral grooves each of which extends from the outboard shoulder main groove beyond a center in width direction of the outboard middle portion without reaching the outboard center main groove, the inboard middle portion is provided with a plurality of inboard middle sipes each of which extends from the inboard shoulder main groove beyond a center in width direction of the inboard middle portion without reaching the inboard center main groove, and the inboard shoulder lateral groove includes a wide portion extending from the inboard tread edge toward the inboard shoulder main groove; and a narrow portion having a groove width smaller than that (W4d) of the wide portion and connecting between the wide portion and the inboard shoulder main groove. a pair of circumferentially extending inboard and outboard center main grooves (3A, 3B) disposed both sides of a tire equator (c) to define a center portion therebetween; a pair of circumferentially extending inboard and outboard shoulder main grooves (3C, 3D) disposed axially outside of the inboard and outboard center main grooves (3A, 3B); a pair of middle portions (4B, 4C) 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; and a pair of shoulder portions (4D, 4E) 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, wherein each of the inboard center main groove, the outboard center main groove and the inboard shoulder main groove has a groove width (W1a, W1b, W1c) in a range of from 10 to 20 mm, the outboard shoulder main groove has a groove width (W1d) in a range of from 2 to 5 mm, the outboard shoulder portion is provided with a plurality of outboard shoulder lateral grooves each of which extends at least from the outboard tread edge to the axially inside of the tire and terminates without reaching the outboard shoulder main groove, the inboard shoulder portion is provided with a plurality of inboard shoulder lateral grooves each of which connects between the inboard tread edge and the inboard shoulder main groove, characterized in that the outboard middle portion is provided with a plurality of outboard middle lateral grooves each of which extends from the outboard shoulder main groove beyond a center in width direction of the outboard middle portion without reaching the outboard center main groove, the inboard middle portion is provided with a plurality of inboard middle sipes each of which extends from the inboard shoulder main groove beyond a center in width direction of the inboard middle portion without reaching the inboard center main groove, and the inboard shoulder lateral groove includes a wide portion extending from the inboard tread edge toward the inboard shoulder main groove; and a narrow portion having a groove width smaller than that (W4d) of the wide portion and connecting between the wide portion and the inboard shoulder main groove.