Inhalational anesthetics are widely used because of rapid induction, good control of anesthesia and rapid recovery from anesthesia. Halothane is no longer used because of life-theatening hepatotoxicity. The mechanism is known as immune-mediated reaction caused by metabolite-modified hepatic protein antigens. Hepatotoxicity due to other inhalational anesthetics such as enflurane or isoflurane is very rare, but cross-sensitization between halothane and enflurane or isoflurane may occur. No other drug hypersensitivity except hepatotoxicity of inhalational anaesthetics is reported till now. We experienced a case that generalized urticaria developed during general anesthesia by enflurane. Intradermal skin test of enflurane was positive, so we confirmed that the mechanism was IgE-mediated immune reaction. This is the first case of drug hypersensitivity other than hepatotoxicity by enflurane.