We studied the effect of adjuvant hepatic arterial chemotherapy with THP-adriamycin (THP) and carboplatin (CBDCA) in patients with hepatocellular carcinoma (HCC). Fifteen patients were treated by intraarterial infusion of THP 30 mg on the second and third week after hepatectomy. CBDCA 450 mg was further injected on the fourth week (group A). Intrahepatic arterial administration of the drug was carried out through the subcutaneously implanted reservoir; one to five courses of the protocol were performed (average 2 times). Transient leukocytopenia occurred in six cases, liver dysfunction in one case, duodenal ulcer in one case and occlusion of the catheter connected reservoir in three cases. Forty-two patients not treated with this protocol postoperatively were employed as historical control (group B). There were no significant differences between group A and B in operative procedures, tumor stage, clinical stage, tumor size and other histopathological findings including nuclear DNA ploidy pattern. The two-year cumulative disease-free survival rate was 78% in group A, which was significantly better than the 55% of group B (p < 0.05). It may be concluded that intrahepatic arterial chemotherapy using THP and CBDCA plays an important role to prevent recurrences of the tumor after hepatectomy in patients with HCC.