A tire having a large number of circular dimples 62 on sidewalls thereof is disclosed. Each dimple 62 has a slope surface 66 and a bottom surface 68. The dimple 62 has a small projection 70. The small projection 70 is annular and is formed on the slope surface 66. A cross-sectional shape of the small projection 70 is substantially a rectangle. The small projection 70 is arranged so as to be concentric with the contour of the dimple 62. The surface area of the slope surface 66 having the small projection 70 is larger than the surface area of the slope surface when it is postulated that the small projection 70 does not exist thereon.