In order to determine the optimal drug administration route in patients with metastatic liver tumor, we studied the pharmacokinetic parameters after intra-arterial or intra-portal adriamycin (ADM) administration. Four patients with metastatic liver tumors were included in this investigation. One catheter was inserted into the gastroduodenal artery for arterial infusion and the other catheter was inserted into the portal vein via mesenteric vein for portal infusion under laparotomy. ADM 30 mg was infused and blood samples were collected from peripheral and hepatic veins. The concentration of ADM was determined with HPLC technique and the pharmacokinetic parameters were analyzed with a three-compartment open model. The parameters analyzed were blood concentration at t0, half-life, rate of elimination, total body clearance, volume of distribution and area under the blood concentration versus time curve. There were no significant differences of the pharmacokinetic parameters between intra-arterial infusion and intra-portal infusion. Also, no differences were observed between the data from peripheral venous blood and those from hepatic venous blood. These data suggest that the drug distributions were almost similar between intra-arterial and intra-portal drug administration in patients with metastatic liver tumor.