Distant metastases are the only clue for diagnosis of malignancy in pheochromocytoma patients. This study was designed to define a secretory profile possibly suggestive of malignancy. Among 79 pheochromocytomas (55 benign, 24 malignant), dopamine-secretion, either exclusive or blended with other catecholamines was found in 34.5% of benign and in 75% of malignant tumors. Dopamine secretion, although if more frequent and more abundant in cases of malignant pheochromocytomas, is therefore not actually diagnostic, but only suggestive of malignancy. It demands life-long follow-up as metachronous metastases may supervene extremely late in the course of the disease.