A run-flat tire is provided in which the tire uniformity is improved, as well as the durability during run-flat traveling may be improved drastically without deteriorating the ride quality during normal traveling. The run-flat tire comprises a side reinforcing rubber layer having a crescent-shaped meridional cross section which layer extends all over or almost all over the both side portions along the inside of the carcass ply. The carcass ply cord contains at least 50% by mass of polyketone fibers, has a heat shrinkage force of 0.1 to 1.8 cN/dtex as a cord subjected to a dipping process, and the heat shrinkage rate of the polyketone fiber in a dry heat treatment at a temperature of 150° C. for 30 minutes is in a range of 0.3 to 6.5%; and the carcass ply includes a weft which crosses the cords arranged approximately along the radial directions, and the weft is cut at a plurality of points at regular intervals along the tire circumferential direction.