A pneumatic tire including five land portions in a tread surface 1 by providing four main grooves in a ground contact region of the tread surface, wherein positions and groove widths of the main grooves are specified together with only one land portion positioned outermost on a vehicle outer side when mounted on a vehicle being formed into a block row, and the other land portions being formed into ribs, and a groove area proportion of the tread surface is larger on a vehicle inner side than the vehicle outer side with a tire equator and center lines of some of the land portions as boundaries.