To our knowledge, there has been only one report pertaining to the efficacy of HCFU for treatment of metastatic lung lesion of HCC, so we reported a case of HCC with lung metastasis which responded to chemotherapy with a single use of HCFU. A 64-year-old male was diagnosed as having HCC with lung metastasis by biochemical examination, abdominal CT, hepatic arteriogram and chest X-P. He had been treated previously with gamma-interferon and mitoxantrone, which were assessed as NC and PD, respectively. Two months after last chemotherapy, HCFU was administrated at a dose of 400 mg/body everyday for 8 months. After 4 weeks metastatic lung lesions showed remarkable regression (47% decrease) and disappeared completely 9 weeks later. The size of primary liver tumor gradually decreased during therapy and revealed marked improvement (85.7% decrease) after about 2 months of this therapy. During these periods serum levels of alpha-fetoprotein dropped from 430 ng/ml to less than 10 ng/ml. He is presently still alive and the duration of the PR attained to 35 weeks. As side effects, hypoproteinemia, anorexia and hot sensation were observed.