One hundred fifty-four consecutive patients with pheochromocytoma (PC, n=137) or paraganglioma (PG, n=17) were treated at our unit. Twenty patients had MEN 2, 15 VRD, and 1 VHL tumors. Twelve had malignant tumors and were classified according to mode of presentation: (1) Distant metastases (n=4); three underwent surgical debulking (with chemotherapy in one); and three had 131I-MIBG therapy. Within 4 years two patients died of tumor progression. (2) Locally advanced disease (n=4), all resected for cure. (3) Malignancy disclosed during follow-up after adrenalectomy with "benign" histopathology (n=4). All patients in groups 2 and 3 developed recurrence 9 (1-17) years after primary surgery; four underwent resection, one remains tumor-free. The others were treated chronically with phenoxybenzamine, combined with 131I-MIBG in one. These eight patients were observed 20 (5-35) years after primary surgery and 11 (1-19) years after recurrence. This series is population-based and may better reflect the natural history of malignant PC/PG than the series from national referral centers. Active surgical treatment and phenoxybenzamine resulted in low tumor-related mortality in groups 2 and 3; five patients died 8-30 years after diagnosis, four of PC/PG (three from group 2 and one from group 3) and one of other causes. We propose tumor uptake studies (MIBG- and octreotide scintigraphy) in patients with nonresectable metastases; to select individual radionuclide therapy data on the expression of CA-transporters/somatostatin receptors may be helpful. To diagnose PC/PG early, screening of adrenal incidentalomas has been suggested. In a regional population-based prospective study, 503 incidentalomas were reported during 18 months, but only one patient with PG was identified.