Single large (>5 cm) hepatocellular carcinoma (HCC) is classified as Barcelona Liver Clinic (BCLC) stage early stage (A). Yet, controversies exist whether single large HCC can be considered as early stage. We have analyzed long-term outcome to see which stage is appropriate for these patients.From 2005 to 2006, 1,546 consecutive patients who were newly diagnosed as HCC (BCLC A or B) at four tertiary hospitals in Korea were analyzed. BCLC A was sub-classified into A1 (single 2-5 cm), A2 (2-3 nodules ≤3 cm), and A3 (single >5 cm). BCLC B1 included patients beyond-Milan criteria, and within up-to-7 criterion. Survival prediction between subgroupings (1: A1 + A2 + A3 vs. B1 and 2: A1 + A2 vs. A3 + B1) was compared based on c-index and Akaike information criterion (AIC).The 5-year overall survival (OS) rate was 62.3, 58.6, 36.8, and 42.0% for A1, A2, A3 and B1, respectively. In multivariate Cox-regression analysis, OS was significantly different between A3 + B1 vs. A1 + A2 (hazard ratio [HR] 1.85; P<0.001), but not between A1 + A2 + A3 vs. B1 (HR 1.19; P = 0.258). For A3, surgical resection showed superior OS over transarterial chemoembolization. Survival prediction was superior in subgrouping 2 (AIC 5727.2; c-index 0.652) than subgrouping 1 (AIC 5766.3; c-index 0.619) even after inverse probability weighting.This large scale long-term follow-up data shows that single large tumor should be considered as intermediate stage in terms of prognosis. However, in terms of treatment, resection might be the first line treatment option.