Objective To evaluate the effectiveness and prognosis of patients in advanced hepatocellular carcinoma (HCC) with portal vein (PV) tumor thrombus received external-beam radiation therapy (EBRT). Methods The clinical data of 126 HCC patients with PV tumor thrombus who were referred for EBRT at our institution from January 2000 to November 2009 were analyzed retrospectively. EBRT was designed to focus on the tumor thrombus with or without primary intrahepatic tumors， to deliver a median total conventional dose of 50 Gy (range of 30-60 Gy). Predictors of survival were identified using univariate and multivariate analysis. Results Unfavorable pretreatment predictors were associated by multivariate analysis with lower albumin and higher α-fetoprotein levels, poorer Child-Pugh liver function classification, poorer intrahepatic tumor control， lymph node metastases， and the two-dimensional EBRT technique. The dose of EBRT showed no significant in both univariate and multivariate survival analysis. Conclusions In patients with HCC， EBRT is effectively prevents progression in cases of PV tumor thrombus， but palliative dose of EBRT is not related to survival.EBRT is not related to survival.