Malignant hyperthermia is a dramatic syndrome that rarely arises during anesthesia and which is still fatal in the majority of cases. It is a hypermetabolic muscle condition characterized by hyperpyrexia and skeletal muscle rigidity. Any potent inhalation anesthetic agent or any skeletal muscle relaxant can trigger this acute catast rophic reaction. A case is presented of a 28 year old femal with a family history of malignant hyperthermia in herrelatives. She sunderwent repair of a retinal detachment under N2O-O2-halothane withcinduction by thiopenthal and succinylcholine. One and half hours after induction, arrhythmia developed and was followed by unstable blood pressure, hyperpyrexia, muscular rigidity. Anesthesia was ended and vigorous emergency treatment was attempted. But she died postoperatively on the 4th day after anesthesia. The etiologic factors, incidence, clinical feature, prevention, treatment and prognosis of malignant hyperthermia are discussed.