We investigated the efficacy of 5-FU hepatic artery infusion (HAI)for patients with unresectable colorectal liver metastasis. Fifteen patients who received HAI between June 2004 and December 2006 were studied. HAI was attempted as first-line chemotherapy in seven patients(Group A)and as second-line or more in eight(Group B). The response rate, time to progression, survival and toxicity were compared with those of 39 patients treated with systemic chemotherapy(18 as first-line: Group C, 21 as second-line or more: Group D). Response rate was 85.7%, 35.7%, 50.0%, and 4.8% in Groups A, B, C, and D, respectively. Time to progression was 12.5 months, 4.7 months, 5.8 months, and 2.3 months, in Groups A, B, C, and D, respectively, and significantly longer in Group A compared with Group C, as well as in Group B compared with Group D. Median survival was 15.4 months, 9.1 months, 11.3 months, and 8.0 months in Groups A, B, C, and D, respectively, and significantly longer in Group B compared with Group D. Grade 3 or 4 non-hematological toxicity was not observed in Group A and B. HAI was effective for the control of unresectable colorectal liver metastasis and improved survival as second-line chemotherapy or more.