A 73-year-old man was followed up for HCV-associated chronic hepatitis and hepatocellular carcinoma (HCC), developed in segment 8 of the liver. Radiofrequency ablation (P-RFA) was used to treat the tumor in June 2004. Afterwards, the patient underwent repetitive transcatheter arterial chemoembolization (TACE) against recurrent tumors 5 times. An abdominal computed tomogram (CT) showed an infiltrative mass in the left liver with tumor thrombus invading into the umbilical portion. Transarterial infusion (TAI) therapy of cisplatin (CDDP) was performed 2 times, in January and June of 2010. The size of the main tumor was decreased according to CT, and tumor marker levels such as AFP and PIVKA-II also decreased, but tumor thrombus of the portal vein developed into the main trunk (Vp4). We started therapy with sorafenib in July, 2010. Two months later, an abdominal CT revelaed further reduction of the main tumor and a shrunken tumor thrombus of the portal vein back to the left lobe. The therapeutic effect of sorafenib against HCC with tumor thrombus of the portal vein continued for 9 months.