Mixed polyurethanes were prepd. in 2-stage reaction of poly(epsilon-caprolactonediol), poly(ethylene glycol) and 1,4-butanediol with NCO(CH(2))(6)NCO and dicyclohexylmethylene-4,4'-diisocyanate at 60-80 degrees C and studied for heat resistance, hardness, d., swelling, degradn. in H(2)O, wetting behaviour and cytotoxicity. The addn. of poly(ethylene glycol) resulted in increasing the biocompatibility of the polyurethane recommended for medical applications.