AIM: To evaluate the outcome predictors of percu- taneous ablation therapy in patients with unresectable hepatocellular carcinoma (HCC), especially to identify whether the initial treatment response contributes to the survival of the patients. METHODS: The study cohort included 153 patients with single (102) and two or three (51) HCC nodules 5 cm or less in maximum diameter. As an initial treatment, 110 patients received radiofrequency ablation and 43 patients received percutaneous ethanol injection. RESULTS: The Kaplan-Meier estimates of overall 3- and 5-year survival rates were 75% and 59%, respectively. The log-rank test revealed statistically significant differences in the overall survivals according to Child- Pugh class (P = 0.0275), tumor size (P = 0.0130), serum albumin level (P = 0.0060), serum protein induced by vitamin K absence or antagonist Ⅱ level (P = 0.0486), and initial treatment response (P = 0.0130). The independent predictors of survival were serum albumin level (risk ratio, 3.216; 95% CI, 1.407-7.353; P = 0.0056) and initial treatment response (risk ratio, 2.474; 95% CI, 1.076-5.692; P = 0.0330) based on the Cox proportional hazards regression models. The patients had a serum albumin level 3.5 g/dL and the 3- and 5-year survival rates of 86% and 82%. CONCLUSION: In HCC patients treated with percutaneous ablation therapy, serum albumin level and initial treatment response are the independent outcome predictors. AIM: To evaluate the outcome predictors of percu- taneous ablation therapy in patients with unresectable hepatocellular carcinoma (HCC), especially to identify whether the initial treatment response contributes to the survival of the patients. METHODS: The study cohort included 153 patients with single ( RESULTS: The Kaplan-Meier estimates of overall 3- and 5 (51) HCC nodules 5 cm or less in maximum diameter. As an initial treatment, 110 patients received radiofrequency ablation and 43 patients received percutaneous ethanol injection. -year survival rates were 75% and 59% respectively. The log-rank test revealed significant statistically in the overall survivals according to Child-Pugh class (P = 0.0275), tumor size (P = 0.0130) P = 0.0060), serum protein induced by vitamin K absence or antagonist II level (P = 0.0486), and initial treatment response (P = 0.0130). The independent predictors of survival were serum albumin level isk ratio, 3.216; 95% CI, 1.407-7.353; P = 0.0056) and initial treatment response (risk ratio, 2.474; 95% CI, 1.076-5.692; P = 0.0330) based on the Cox proportional hazards regression models. The patients had a serum albumin level of 3.5 g / dL and the 3- and 5-year survival rates of 86% and 82%. CONCLUSION: In HCC patients treated with percutaneous ablation therapy, serum albumin level and initial treatment response are the independent outcome predictors.