We investigated the characteristics of tumor responses of hepatocellular carcinoma (HCC, n = 14) and colorectal hepatic metastasis (CHM, n = 10) to high dose hepatic arterial chemotherapy using direct hemoperfusion under hepatic venous isolation. Adriamycin was given at doses ranging from 100 to 150 mg/m2. During drug infusion, two patients with HCC and three with CHM were treated by balloon-occluded arterial infusion (BOAI). Computerized tomographic findings after treatment were compared between the two diseases. In addition, response characteristics in each disease were investigated in relation to tumor factors such as size, capsule formation, vascularity and macroscopic type. Eight (57%) out of 14 patients with HCC showed either size reduction (n = 5) or liquefaction (n = 3), while the remaining six patients showed no apparent changes. On the other hand, seven (70%) of 10 patients with CHM showed liquefaction without any evidence of tumor size reduction. Regardless of the disease, all patients treated with BOAI had liquefaction as a sign of tumor responses. Based on these observations, it is concluded that response characteristics may differ depending on tumor factors such as vascularity and the nature of the treatment as represented by BOAI.