Resection of bilateral pheochromocytomas of a 33-year-old man with Sipple syndrome was scheduled. Oral prazosin was started twenty days before the operation and increased to a maintenance dose of 6 mg per day. Oral lavetalol 300 mg per day was added for five days before the operation because prazosin alone was insufficient. Intravascular volume was expanded with two units of stored whole blood per day for four days before the operation for preoperative preparation. Anesthesia was induced with thiamylal 250 mg and vecuronium bromide 9 mg, and maintained with enflurane, nitrous oxide and oxygen. Phentolamine, labetalol and nitroglycerin were used for treatment of hypertensive crises during operation and anesthesia. To combat hypotension which follows the resection of the tumor, continuous infusion of norepinephrine was used for four hours after the operation. There were no hypotensive periods and no complications. After removing bilateral pheochromocytomas of the adrenals, treatment of full adrenocortical replacement therapy was performed. Concurrent use of alpha-and beta-adrenergic blocking agents was important for successful anesthetic management for the resection of pheochromocytoma.