In non-resectable liver malignancies, concurrent administration of degradable starch microspheres (DSM) and anticancer drugs via hepatic artery has been suggested as a method to increase the concentration of drugs in tumor tissue. DSM also has been known to increase the temperature of tissue when administered at the time of hyperthermia. In the light of these findings we have studied the effect of hepatic arterial infusion of 5-FU and mitomycin C and local hyperthermia in combination with hepatic arterial flow arrest with DSM for the treatment of hepatoma in 11 patients and metastatic liver cancer in 38 patients. Of the 8 patients having hepatoma with increased AFP, all the patients showed a decrease of AFP following the therapy with an average ratio of 65% decrease. Of the 33 patients with hepatic metastasis with increased CEA, 32 patients (96%) showed a decrease of CEA following the therapy (control group with infusion chemotherapy and hyperthermia without DSM: 58%) with an average decrease ratio of 59% (control group: 43%). Of the 26 patients with increased CA 19-9, 22 patients (84%) showed a decrease of CA 19-9 (control group: 75%) with an average decrease ratio of 52% (control group: 29%). This pilot study suggests that the concurrent hepatic arterial infusion of 5-FU, mitomycin C and DSM with local hyperthermia may have the potential to improve selective regional drug effect.