The hemodynamic changes of portal vein before and after intra-arterial infusion of ethanol iodized oil emulsion (EIOE) were studied in 4 healthy dogs. Segmental transcatheter arterial embolization (TAE) using EIOE was performed in 55 patients with hepatocellular carcinoma (HCC). Twenty patients subsequently underwent surgery. It was concluded that segmental TAE might lead to double embolization of both hepatic arteries and portal veins. It is a more effective therapeutic method for HCC localized in one or a few segments, as compared with conventional TAE.