Transcatheter arterial chemoembolization (TACE) is used in the treatment of hepatocellular carcinoma; however, it has limited effect on portal vein tumor thrombus (PVTT). The purpose of this study was to assess the feasibility and efficacy of radiotherapy targeting the PVTT after TACE for the tumor in the hepatic parenchyma. TACE was performed using epirubicin hydrochloride, iodized poppy seed oil, and gelatin sponge particles. Radiotherapy was performed targeting the PVTT to a total dose of 50 Gy in 25 fractions during 5 weeks. Twenty consecutive patients were treated with this combined treatment. Sixteen of 20 patients could complete the planned radiotherapy. Partial response was observed in 10, no change in 4, and progression in 6. The response rate was 50% (95% CI 28-72%). The 1-year overall survival rate was 25% (95% CI 6-44%), and the median survival time was 5.3 months. It was difficult to determine the late toxicities because of disease progression and additional TACE, and only one patient died without disease progression. Radiotherapy after TACE is feasible for patients with hepatocellular carcinoma and PVTT. The survival figure, however, is still dismal, and further investigation is needed to establish the best combination of treatment modalities.