The neuroleptic malignant syndrome (NMS) is a potentially fatal complication of antipsychotic drugs. It is characterized by severe muscular rigidity, hyperthermia, and autonomic disturbances. Neuroleptic malignant syndrome is easily confused with other health problems; distinctions between it and malignant hyperthermia, heatstroke, and lethal catatonia are made. The relevant literature is reviewed; a case history is presented; and implications for nursing care (e.g., early detection) are discussed.