BACKGROUND: Malignant hyperthermia (MH) is a hypermetabolic disorder of skeletal muscle that manifests after exposure to triggering episodes such as halothane or succinylcholine. The first case was reported in Australia on 1960 by Denborough. In Korea the first case report was made by Lim on 1971. The authors retrospectively analysed the reported cases of MH and/or masseter muscle rigidity in Korea for the establishment of appropriate diagnostic criteria and rapid treatment. METHODS: Twenty-one cases of MH and 2 cases of masseter muscle rigidity were analysed retrospectively form 1971 to 1995. These cases were reported in Journal of Korea Society of Anesthesiology and Journal of Research Institute of Medical Science of Korea. The analyzed items were age, department, anesthesia, symptoms and signs, drugs for treatment, history of patient and family and prognosis of MH. RESULTS: The incidence of MH was higher in male patients below the 4th decade of life. The rate was 0.6 per year from 1971 to 1995. In nineteen patients, inhalation anesthetics with succinylcholine were suspected as triggering agents and 4 patients' conditions were related to spinal anesthesia by tetracaine. Only one case of MH occured within 10 min. after induction, but 22 cases occured during operations or the recovery period, and one case in the ward. The most common initial signs were muscle rigidity, high fever with arrhythmia and increased blood pressure. Related laboratory findings were acidosis, elevated end tidal CO2, and hyperkalemia. Six cases had family histories or past histories related to MH. CONCLUSIONS: The incidence of MH is progressively increasing in Korea. But MH will be prevented and treated effctively. So we should prepare a monitoring system for early detection and a supply of dantrolene for treatment. These precautions will spread nationwide and will need the support of the anesthesiology society and the goverment.