A 73-year-old man underwent a sigmoid colon resection and an insertion of a hepatic arterial infusion catheter for multiple liver metastases from sigmoid colon cancer. After the hepatectomy, the patient was detected a lung metastasis and was scheduled to undergo mFOLFOX6 chemotherapy. The tumor lesion was reduced once in size, but it has grown again after the chemotherapy. So, we underwent a stereotactic radiotherapy (60 Gy/10 Fr). The tumor lesion became a scar and the patient was doing well without any recurrence at 21 months after undergoing stereotactic radiotherapy. Lung resection has a better result than other treatments for a lung metastasis caused from colon cancer, but there are some cases with no indication of the operation due to a complication. Stereotactic radiotherapy can be an effective treatment for lung metastasis from colon cancer with no indication of the operation.