We report the case of a 60-year-old woman with multiple lymph node metastases after ascending colon cancer who received radiation therapy and then chemotherapy with S-1. She was diagnosed with lymph node metastasis of the para aorta and left upper clavicle 10 months after surgery. We performed radiation therapy for the left upper clavicle (64 Gy)and para aorta (40 Gy). Consequently, we administered S-1(100mg/day)orally. After three months, the upper clavicle lymph nodes had disappeared and the para-aortic lymph nodes reduced. All metastatic lesions disappeared after 10 months. She survived for 32 months after the radiation therapy.