Pheochromocytoma is an infrequent cause of hypertension. In spite of its rarity, pheochromocytoma has assumed notorious importance because or a wide variety of clinical features associated with this syndrome. Hypertension remains the most important clinical lead. The presence of other features, such as severe headache, perspiration, palpitations or orthostatic hypotension, makes the diagnosis of pheochromocytoma likely. The diagnosis of this condition can be made with greater certainty than that of any other form of secondary hypertension. Pharmacologic tests are no longer used for evaluation purposes. Biochemical tests are the most important aids to diagnosis, provided highly specific methods are used to determine the levels of urinary catecholamines or their metabolites. Interference by various drugs should be avoided. Most of the pheochromocytomas are found in the abdomen, predominantly in the adrenals. Successful outcome of surgery depends critically on adequate preoperative preparation of the patient with adrenergic blocking drugs and proper intraoperative care. Surgery should only be performed in an institution with experience in treating these tumors. Invasive localizing procedures could be dangerous in patients with pheochromocytoma and are best avoided. Medical therapy proves to be quite successful for those patients who are unable or unwilling to undergo surgery and for those with demonstrated malignant tumor. The postoperative course in most instances is uneventful. The physician should be aware of familial forms of pheochromocytomas and screen all the hypertensive members of the patient's family for the presence of this condition. Pheochromocytoma, with its multiple facets, presents a challenge to the clinician; however, with prompt diagnosis and proper treatment, pheochromocytoma can often be cured. The improved management of patients with this potentially lethal condition is the result of better knowledge of biochemical pharmacology, improved preoperative, surgical and postoperative care.