A run-flat tire is provided with a reinforcing cord layer adjoining the radial carcass at least from the belt end to the maximum width portion of the tire side portion; the cord constituting the reinforcing cord layer is nylon 66 cord, cellulose fiber cord, PET cord, PEN cord or aramid/nylon 66 hybrid cord, and has a cord angle of less than 10° with respect to the tire radius direction; and the elastic modulus of the cord pulled out from the tire at a temperature of 25° C. under the conditions of a load of 3 N is not higher than 40 cN/dtex, and the thermal shrinkage stress σ (cN/dtex) at a temperature of 177° C. and the elastic modulus E (cN/dtex) at a temperature of 177° C. under the conditions of a load of 10 N satisfy the following conditions: σ+0.025E≧0.36, 40≧E≧8, and σ≧0.05.