We report a case in which a 63-year-old male patient with pheochromocytoma developed persistent hypotension during surgery despite rapid volume replacement and administration of vasopressors. The patient was prepared for surgery with phenoxybenzamine for 13 days. Anesthesia was induced with thiopental sodium and maintained with N2O, O2, and enflurane. Sodium nitroprusside (SNP) was initiated and titrated based upon intraarterial blood pressure. Hypertensive episode during tumor manipulation was effectively managed by increased infusion of SNP. After surgical removal of tumor, this patient developed profound hypotension, which was aggressively managed by intravenous administration of crystalloid and blood as well as dopamine and epinephrine. However, this hypotension was persistent and aggravated. Accordingly, Infusion of norepinephrine (Levophed(R))was started and then the patient recoverd from his hemodynamic aberrations. We conclude that the cause of the persistent hypotension was cumulative and residual effect of preoperative phenoxybenzamine. Therefore, norepinephrine should be readily available for the treatment of hypotension resistant to other pharmacologic interventions.