A 56-year-old man with abnormal chest X-P and stool occult bleeding was admitted. Colonoscopy detected rectal cancer and sigmoid al polyps. The biopsy results suggested that the rectal lesion was well- to moderately-differentiated adenocarcinoma and the sigmoidal polyp contained well -differentiated adenocarcinoma. CT scan revealed multiple lung, liver and lymph node metastasis. We judged the case to be inoperable and decided to start systemic chemotherapy (FOLFOX4). After treatment with chemotherapy, the tumor shrank and metastatic lesions disappeared. Low anterior resection was done, and final pathological examination revealed a complete response of the main tumor by treating with FOLFOX4.