Forty-one patients who had pheochromocytoma are described. These patients represent the experience of the authors over the last 19 years. The diagnoses, investigations, treatments, and pitfalls of this study and the management of these patients are described. The most sensitive screening test was the urinary measurement of catecholamines, vanillylmandelic acid (VMA), and metanephrines. The most useful localizing procedure was the metaiodobenzylguanidine (MIBG) scintigraphy and computed tomography (CT). After careful alpha and beta adrenergic blockade in 32 patients, no complications occurred during or after tumor resection. When this procedure was ignored even in patients who had normal blood pressure before surgery, severe cardiovascular complications occurred and two patients died. In familial pheochromocytoma, bilateral adrenalectomy with preservation of normal adrenal cortical tissue when possible may be the method of choice, but careful follow-up is warranted.