We report a case of complete remission of relapsed rectal cancer liver metastasis after systemic chemotherapy successfully treated by radiofrequency ablation (RFA). A 60-year-old man was diagnosed as having rectal cancer with colonoscopy and as solitary liver metastasis with enhanced CT. After primary tumor was resected, modified FOLFOX6 chemotherapy was performed. A complete response (CR) was observed after the eighth course, and the chemotherapy was finished at the twelfth course. Recurrence of liver metastasis was showed after the chemotherapy for six months, so RFA was performed without any complications. He is living without relapsing for eight months. We basically performed first was systemic chemotherapy to liver metastasis of colorectal cancer, and performed a local treatment including resection, if necessary. We suppose that RFA after systemic chemotherapy is one of the useful treatment strategies for liver metastasis of colorectal cancer, because RFA is less invasive than resection and a discontinuation of the drug is not required for RFA.