A 46-year-old male patient had recurrent episodes of generalized pruritic wheals during hemodialysis. He has experienced urticaria during hemodialysis whenever he used a capillary dialyser sterilized by ethylene oxide(EO, Polysulfone-) gas which is used to sterilize hemodialysers and other medical equipment. On the other hand, capillary dialyser sterilized by Gamma ray (Hemophad) has not evoked urticaria. Although the presence of EO-specific antibodies was not detected, urticarial rash never developed when the equipment was switched to a gamma-sterilized one. We herein report a case referred to ethylene oxide induced cutaneous hypersensitivity during hemodialysis.