A 45-year-old female was scheduled for left adrenalectomy because of a pheochromocytoma. Preoperative general condition was well controlled with α- and β-blockers. Anesthesia was induced with thiamylal and vecuronium, and maintained with isoflurane (0.5~3%) and nitrous oxide in oxygen. Blood pressure was controlled with nicardipine and α-blocker during the manipulation of the tumor. After removal of the tumor, dopamine and norepinephrine were used. We used transesophageal echocardiography (TEE) to determine the fluid administration rate and doses of catecholamine. We could observe the wall motion and the mass of the heart, and see changes of the left ventricular enddiastolic volume, the cardiac output and the stroke volume. TEE monitoring seems to be very useful during the resection of pheochromocytoma.