PURPOSE: To investigate the effects of low-dose FP (5-Fluorouracil[5FU]+Cispatin[CDDP]) therapy through a percutaneously implanted intra-arterial port system in patients with advanced hepatocellular carcinoma(HCC). MATERIALS AND METHODS: Twenty-five patients with advanced HCCs and portal vein thrombosis, or large HCCs which were unresectable or for which transarterial chemoembolization was thought to be ineffective, underwent intra-arterial port implantation. The mean maxinal diameter of these tumors was 13.7 (range, 5-21.5) cm, and they were located at the right lobe (n=18), the left lobe (n=3), or throughout the liver (n=4). Tumor thrombosis was detected in the main (n=14), right (n=3) and left portal vein(n=1), the right portal vein and inferior vena cava(n=2), and the inferior vena cava(n=1). The four others patients had no portal vein thrombosis. All intra-arterial port implantations were performed percutaneously in the angiographic ward through the right or left common femoral artery. The port chamber was implanted in the inguinal area and fixed using histoacryl. For intra-arterial chemotherapy, 5-FU (250 mg/day) and CDDP (10 mg/day) were used for five days every four weeks. In order to observe changes in tumor size, follow-up CT scanning was performed every two months. RESULTS: Implantation of the port system was successful in all cases, and patients underwent between one and eleven (mean, 3.9) sessions of chemotherapy. Port and catheter-related complications, namely dislodgement of the catheter(n=2), wound infection(n=2), migration of the coil(n=1) and catheter occlusion(n=1) occurred in six patients (24%), and chemotherapy-related complications, namely liver failure(n=3) and gastric ulcer bleeding(n=1), in four (16%). A complete response, i.e. the disappearance of tumor thrombosis of the portal vein, was achieved in one patient (4%), a partial response in three (12%), and a minor response in four (16%); the overall response rate was 32% and the mean survival period was 7.6 months. CONCLUSION: Low-dose FP therapy through a percutaneous intra-arterial port system may be one way of effectively treating advanced HCC patients who cannot undergo surgery or effective trans-arterial chemoembolization.