The significance of hepatic arterial infusion chemotherapy for unresectable liver metastases from colorectal cancer was evaluated in 50 patients, who received either of the following regimens: 1 shot 5-FU + epirubicin + MMC (FAM group); hepatic arterial infusion of 5-FU for 2 hours + MMC (MF group); hepatic arterial infusion of 5-FU for 2 hours (5-FU group). There were no differences in the clinicopathological backgrounds of the patients among the groups. The mean survival time was 10.3 months, 16.0 months and 16.2 months in the FAM, MF and 5-FU groups. The effective percentages were 0%, 40% and 31% in the FAM, MF and 5-FU groups and the survival time of the effective cases was 18.1 months and 21.8 months in the MF and 5-FU groups. The MF group and 5-FU group showed significant improvement in prognosis. Concerning side effects, myelo-suppression and gastrointestinal toxicity appeared frequently in the MF group. In conclusion, 2-hour continuous hepatic arterial infusion with low-dose 5-FU for unresectable liver metastases from colorectal cancer may be helpful for improvement of prognosis.