We report a case of ascending colon cancer successfully treated for synchronous liver metastases with mFOLFOX6 after a resection of the primary tumor. A 79-year-old woman was diagnosed as having an ascending colon cancer with synchronous liver metastases. After right hemicolectomy, she was treated with mFOLFOX6. A partial response was observed after the fifth course and CEA decreased to a normal range (8 ng/mL). A complete response was observed after the ninth course and the treatment finished at the twelfth course. Sequentially, she was treated with UFT/LV/PSK after three courses of FOLFIRI regimen. The patient is alive without recurrence.