Malignant hyperthermia is a hypermetabolic, frequently fatal syndrome triggered by anesthetic drugs that occurs in genetically susceptible persons. Fatalities have been reported in patients receiving dental treatment with general anesthesia. The syndrome may also be triggered by stress, exercise, muscle injury, mild infections, and other nonpharmacologic agents or stimuli in conscious patients. Treatment is symptomatic and empiric, and potential reactors are not easily identified. However, criteria for identifying most susceptible persons have been established, and therapeutic agents for prophylaxis and treatment, which appear to be effective, are available. In this paper we report experiences with the syndrome and discuss an overview of its features, criteria used for identifying susceptible persons, prophylaxis, diagnostic features, and procedures to be followed should the syndrome develop.