A 54 year-old woman underwent resection of pheochromocytoma under general anesthesia. Following induction of anesthesia with intravenous thiopental sodium, succinylcholine iodide was administered intravenously and endotracheal intubation was performed. Anesthesia was maintained with nitrous oxide, oxygen and diethyl ether using a semi-closed carbon dioxide absorption circle system. The course of anesthesia was rather stormy, reflected by hypertension, arrhythmia and hypotension, but the patient tolerated anesthesia well.