A 66-year-old woman was admitted to our hospital because of general fatigue and icterus. PTC findings showed irregular stenosis of hilar bile duct. Abdominal CT scan showed a dilatation of the intra-hepatic bile duct and a tumor around hilar bile duct. We diagnosed it as hilar bile duct carcinoma, and although we operated it was unresectable because of the metastasis of a para-aorta lymph node and duodenal invasion. We started chemo-radiotherapy with a total dose of 45 Gy and gemcitabine. The tumor and para-aorta lymph node were remarkably decreased, and tumor marker CA 19-9 was also decreased to within the normal range. The patient had a peritoneal dissemination 10 months after the chemo-radiotherapy and survived 20 months.