Pheochromocytoma of the adrenal gland can be the cause of massive and lethal retroperitoneal haemorrhage presenting as acute abdomen. Here we report a case of retroperitoneal hematoma, with concomitant peritoneal spillage, due to the spontaneous rupture of a silent pheochromocytoma. The main clinical findings of this disease will be described. Therapy and prognosis will be also discussed.