A 69-year-old woman who had a history of chronic hepatitis C, autoimmune hemolytic anemia and myelodysplastic syndrome was treated with sorafenib at a daily dose of 400 mg for HCC with multiple lung metastases. Nonetheless, elevated serum tumor markers further increased (alpha fetoprotein from 121,100 to 348,660 ng/ml and protein induced by vitamin K absence/antagonist-II from 3435 to 29,357 mAU/ml), and lung metastatic lesions on chest X-ray showed no improvement after 2 months of sorafenib treatment. Sorafenib was discontinued because of adverse events with diarrhea, fatigue, and severe anemia due to bleeding from stomach telangiectasia. Hand-foot syndrome was mild. Thereafter, the tumor markers rapidly decreased to almost normal range, and the lung and liver tumors markedly shrunk and disappeared without any other cancer treatments. Her tumors remained in complete remission for 17 months until an intrahepatic recurrence occurred. This unique course of metastatic HCC indicated that antitumor mechanisms other than the direct anticancer effect of sorafenib contributed to tumor shrinkage.