Various treatments were performed in 14 patients with liver abscess, and their clinical effects were compared. The treatments were intra-arterial antibiotic infusion therapy (Group A, 4 patients), intra-arterial infusion therapy plus percutaneous drainage of the abscess (Group B, 4 patients), and intravenous antibiotics alone (Group C, 6 patients). The period from the beginning of treatment to negative conversion of CRP* (period until cure) was compared among the groups. Groups A and B had received intravenous antibiotics for a mean of 10 days and 16 days, respectively, but the treatment was ineffective. The mean period until cure from the beginning of intra-arterial infusion therapy was 36 days for Group A and 18 days for Group B. In Group C, the mean period until cure was 28 days. All patients recovered, and recurrence was observed in only one patient. Although liver abscess can be treated successfully in many patients by intravenous antibiotics alone, intra-arterial therapy is effective in those in whom intravenous therapy is not effective.