A 51-year-old male of von Recklinghausen's disease presented with huge retroperitoneal hematoma caused by spontaneous arterial rupture. He died of uncontrollable hemorrhage during the operation. Gross appearance of aorta, renal artery, celiac artery, pulmonary artery and lumbar artery were extremely fragile, and there was a complete rupture between aorta and lumbar artery. On the microscopic examination, significant medial dysplasia were demonstrated in these arteries. Arterial stenosis is well-known vascular complication in von Recklinghausen's disease. Spontaneous rupture of major artery, however, has been extremely uncommon. This is the 26th case reported in the world literature, and 21th case in the Japanese literature.