Continuous arterial infusion chemotherapy using implantable reservoir was performed for unresectable liver metastases from colorectal cancer and the therapeutic effects, side effects and complications were evaluated. Eleven patients were treated with four kinds of arterial infusion courses that mainly consisted of 5-FU. The arterial infusion courses were discontinued in 2 patients because of nausea and vomiting, and in one patient because of diarrhea. The catheters were dislocated in 2 patients and another 2 developed fistulous between the hepatic artery and bile duct. Three patients developed duodenal ulcer. Serum CEA was reduced in 4 patients (36%). After all, response rate was 9% (1/11). The one-year survival rates of all cases and cases treated with more than 4 courses were 36.3% and 80.0%, respectively.