Tires are improved against puncture damage by at least partially filling the inside of the tire with hollow spheres which contain a gas and whose thin shell consists of synthetic material, these spheres having a diameter of between 0.01 and 0.04 mm. and a density of 0.005 to 0.25 g/cc., and/or by lining at least a portion of the surface of the inner wall of the tire with a strip of composite material of low density comprising a suspension of said hollow spheres in a mass of liquid or pasty synthetic material of low molecular weight.