A process for producing a shaped article of a non-cellular or microcellular polyurethane elastomer by reaction injection molding by using at least two components of (A) a polyol component comprising a high molecular weight polyol and a chain extender as essential ingredients and (B) an isocyanate component comprising a polyisocyanate compound as essential ingredient, characterized in that substantially all or at least 80% by weight of said high molecular weight polyol is composed of a polyoxyalkylene polyol, and the polyoxyalkylene polyol is a single or mixed polyoxyalkylene polyol which has an average hydroxyl number of from 2.0 to 3.5 and an average hydroxyl value of from 15 to 60 and contains at least 5% by weight, in an average, of oxyethylene groups at the terminal portions of the oxyalkylene chain and in which the total oxyethylene group content is, in an average, less than 21% by weight and the average unsaturated monool content is at most 0.085 meq/g.