A process for producing a polyurethane shoe sole having an article density of 100 to 350 g/L and being made from an organic polyisocyanate, a polyol, a blowing agent consisting of water, and optionally a crosslinking and/or chain-extending agent, a catalyst, and other auxiliaries and/or additives. First, polyisocyanate, polyol and any crosslinking and/or chain-extending agent are mixed and reacted at a temperature of 110° C. to 180° C. to give a prepolymer having polyisocyanate groups. Second, the isocyanate-terminated prepolymer obtained and any remaining polyisocyanate are mixed with any remaining polyol, blowing agent comprising water, and any remaining crosslinking and/or chain-extending agent and also any catalyst and other auxiliaries and/or additives are introduced into a mold and allowed to fully react to give a polyurethane shoe sole.