Scintigraphy with 131I-m-BG was used in 4 children with a history of multiple pheochromocytomas in order to localize further catecholamine-producing tumors prior to surgery. We overlook 7 scintigraphies without any side effect. Phenoxybenzamine did not interfere with tracer uptake into tumors. Scintigraphic localization of even smallest extra-adrenal tumors was successful in all cases. In most cases we were dealing with benign pheochromocytomas, but also a ganglioneuroma and metastases of a malignant pheochromocytoma could be revealed. Scintigraphy is a reliable technique for tracing pheochromocytomas and catecholamine-producing ganglioneuromas. It seems to be superior to other non-invasive techniques, furthermore, invasive techniques bearing higher risks may be suspended.