Twelve patients with unresectable primary liver cancer (hepatocellular carcinoma and cholangiocarcinoma) and postoperative recurrence of primary liver cancer received continuous arterial or systemic infusion of low-dose CDDP/5-FU. This infusion chemotherapy was continued for five days, discontinued for two days, and repeated four weeks as one course basally. The partial response rate in patients with HCC or CCC treated with intra-arterial infusion was 20% and 33%, respectively. The rate in patients with HCC or CCC treated with systemic infusion was 0% and 33%, respectively. The response rate included decrease of tumor markers in all patients with HCC or CCC was 33% and 67%, respectively. These results suggest that low-dose CDDP/5-FU therapy may be effective in patients with CCC. Severe side effects such as gastro-duodenal ulcer (4 cases) and pseudomembranous colitis (1 case) were observed. The careful management of side effects should be required during this therapy.