The authors experienced a case of myoglobinuria accompanied by generalized myalgia and mild fever that developed 3 hours 30 minutes after general anesthesia. Tracheal intubation was done smoothly 5 minutes after injection of thiopental sodium(275 mg) and pancuronium bromide(6 mg), and anesthesia was maintained with ethrane/N2O/O2(1.5-2%/21/21/min). There was no specific event except tachycardia and fluctuation of blood pressure throughout operation. In this case, we assume that the myoglobinuria is a presentation of the sign of an abortive type of malignant hyperthermia. However, it was not confirmed. We had good patient outeome with the supportive measures of hydration and diuresis. The patient was discharged twenty three days after operation without any complication.