Abstract: The present invention concerns a new, unconventional, mold-binding, water solidified polyurethane cast to be used in orthopedic departments for the correction of deformities, fixation of fractured limbs and joints, and mollification of affected parts, as well as the method of its preparation. The chief constituent, a polyurethane prepolymer, contains a stabilizer that can prolong appreciably the storage period of the cast material, maleic anhydride, and a mixed catalyst for control of hardening time, bis(2-morpholinoethoxy)ethane and anhydrous potassium carbonate.