We report a case of recurrent rectal cancer with multiple lung metastases successfully treated with S-1 and CPT-11 combination chemotherapy. Rectal amputation was carried out on the rectal cancer patient, a 63-year-old man. CT scan revealed multiple lung metastases after 20 months of surgery. The patient was treated with S-1 and CPT-11 combination chemotherapy. S-1(100mg/body/day)was orally administered for 2 weeks followed by a 1-week interval, and CPT-11 (120 mg/body on day 1)was simultaneously administered. After completion of 8 courses, CT scan showed no lung metastases, and the patient was judged to have achieved a complete response (CR). The CR interval was maintained for twelve months until 20 courses of chemotherapy had been completed. This chemotherapy was expected to have a potent therapeutic efficacy for recurrent rectal cancer, considering the convenience, cost benefit and no severe adverse event.