AIM: To evaluate the efficacy of radiotherapy (RT) in patients with advanced unresectable hepatocellular carcinoma (HCC). METHODS: A total of 65 patients were treated with RT in the Korea University Medical Center. The median age of the patients was 60 years, and 86.2% were men. 18.5% and 81.5% of the patients were diagnosed as TNM stage Ⅲ and Ⅳ-A, respectively. Treatment response was assessed 4 mo after initiation of RT. Tumor regression rate 1 mo after initiation of RT (TRR1m) was also assessed. Duration of survival was calculated from the initiation of RT. RESULTS: The objective treatment response was 56.9%. The 12 mo survival rate was 34.7%. Predictive factors for survival were Child-Pugh grade, α-fetoprotein level and treatment response. An objective response was achieved more frequently in patients with TRR1m ≥ 20% than in those with TRR1m < 20% (P < 0.001). CONCLUSION: RT is effective in treating advanced HCC with a tumor response rate of 56.9%. AIM: To evaluate the efficacy of radiotherapy (RT) in patients with advanced unresectable hepatocellular carcinoma (HCC). METHODS: A total of 65 patients were treated with RT in the Korea University Medical Center. The median age of the patients was 60 years, Tumor regression rate 1 mo after initiation of RT (TRR1m), 86.2% were men. 18.5% and 81.5% of the patients were diagnosed as TNM stage Ⅲ and Ⅳ-A, respectively. Results of survival was calculated from the initiation of RT. RESULTS: The objective treatment response was 56.9%. The 12-mo survival rate was 34.7%. Predictive factors for survival were Child-Pugh grade, α-fetoprotein level and treatment Response. An objective response was achieved more frequently in patients with TRR1m ≥ 20% than in those with TRR1m <20% (P <0.001). CONCLUSION: RT is effective in treating advanced HCC with a tumor response rate of 56.9%.