During the past 20 years (1970-90), we had 24 patients with pheochromocytoma: 19 diagnosed clinically and 5 post-mortem. Their ages ranged from 17 to 74 (mean, 43.2 years). Males (n = 14) outnumbered females (n = 10), a 1.41:1 M:F ratio. A majority were symptomatic (95%), with a typical triad of headaches, palpitations and diaphoresis. Most frequent finding was hypertension (95%). It was sustained in 60% and paroxysmal in 35%. In 6 patients (25%) pheochromocytomas were bilateral, all familial. Fifteen were solitary adrenal tumors (63%); 3 (12.5%) were extra-adrenal: 2 intra-abdominal, and 1 cardiac paraganglioma of right atrium. Of 6 familial cases, 4 were associated to Von Hippel-Lindau (VHL) disease, while 2 were multiple endocrine neoplasia (MEN-II) patients. All familial cases were bilateral and in the adrenals. There were no malignancies. Among the 19 clinical cases pre-operative Dx was made by positive urine VMA or catecholamines urine levels: (95 and 100% sensitivity respectively). Preoperative visualization by CT or MRI was done in 62% of the most recent patients. In 5 earlier cases the diagnosis was made post mortem: 3 died of cerebral hemorrhage, 1 with a pons infarct and 1 with congestive heart failure (CHF). There were 2 post-operative deaths and another died 13 years later from thyroid medullary carcinoma. Of the 19 operated, 13 (68%) were cured. Thus pheochromocytomas retain considerable morbidity and some mortality. These rare tumors constitute a clinical diagnostic challenge yet a rewarding therapeutic experience for the alert physician.