A pneumatic tire which comprises a tread portion with a pair of tread edges, and a tire shoulder extending radially inwardly from one of the tread edges, provided with a curved surface comprising a convex curve, wherein, on a cylindrical surface centered on the tire axis and intersecting the curved surface, the convex curve swells axially outwards and has a curvature, and the curvature gradually diminishes towards the radially inside from the tread edge. It is possible that the tread portion is provided along the tread edges with a circumferentially extending rib and/or a circumferential row of blocks. In case of circumferential rib, the rib is provided with the curved surface comprising a plurality of the convex curves and a plurality of convex curves alternating therewith so that the curved surface is waved in the tire circumferential direction. In case of blocks in a circumferential row, it is preferable that each block is provided with the curved surface comprising at last one convex curve.