Although pheochromocytoma in a patient with endstage renal disease (ESRD)is considered extremely rare, we recently encountered 4 ESRD patients with pheochromocytoma. Three were symptomatic, and in the fourth patient the tumor was discovered as an adrenal incidentaloma. Plasma catecholamine levels were significantly increased in two patients. In each case, 131I-MIBG scintigraphy showedaccumulation of the radionuclide in the adrenal tumor, which was identified by MRIor CT scanning, and adrenalectomy was conducted without serious complications. Although paroxysmal hypertension is a commonsymptom in patients with ESRD, pheochromocytoma must be eliminated by careful evaluation.