We analyzed the effectiveness and adverse effects of hepatic arterial infusion chemotherapy (HAI) for patients with liver metastasis of colorectal cancer in order to clarify the rules of HAI. We provided HAI to 72 patients after hepatic resection and to 119 patients with unresectable liver metastases. The preventive effect on hepatic recurrence was recognized in the group administered more than 15 g of 5-FU (total dose). The response rate of patients with unresectable metastases was 60.3%. Adverse effects were observed in 65.8% of the patients. It is important to establish a follow-up system in each hospital to treat the patients as soon as possible when patients develop an adverse reaction.