We investigated the efficacy and limitation of hepatic arterial infusion (HAI) chemotherapy for colorectal liver metastases. In terms of prophylactic HAI following curative resection of liver, the 5-year disease-free survival of HAI group (12 g of 5-FU administered in 6 weeks) was 66.7%, whereas that of randomly selected control group was 20.0%. The difference was statistically significant (p = 0.045). Recurrent disease was confirmed in three cases of HAI group (one in liver) and in 8 patients of the control group (6 in liver). However, the overall survival was not significantly different between the groups. Thus, the short-term HAI of 5-FU is effective in decreasing the recurrence of disease. As for the treatment of unresectable liver metastases, some patients received HAI of 5-FU (1,000-1,500 mg/w) showed prolonged survival with partial remission of the disease. However, the 1-, 2-, and 3-year cumulative survival of HAI group (n = 27) was 69.3, 34.1 and 11.4%, respectively, against 61.3, 22.6 and 9.4%, respectively, in the transarterial embolization (TAE) group (n = 31). Therefore it is important to estimate the effect in the early phase of HAI, and aggressively continue the treatment in selected patients for whom it is suitable.