Background: /Aim: The profile of patients with hepatocellular carcinoma (HCC) has changed globally; the role of etiology in predicting prognosis of HCC patients remains unclear. We aimed to analyze the characteristics and prognosis of Korean patients with HCC according to disease etiology. Methods: This retrospective observational study included patients diagnosed with HCC between 2010 and 2014 in a single center in Korea. Patients with HCC aged <19 years old, had coinfection with other viral hepatitis, had missing follow-up data, were Barcelona Clinic Liver Cancer stage D, or died before 1 month were excluded. Results: A total of 1,595 patients with HCC were analyzed; they were classified into the hepatitis B virus (HBV) group (1,183 [74.2%]), hepatitis C virus (HCV) group (146 [9.2%]), and non-B non-C (NBNC) group (266 [16.7%]). The median overall survival of all patients was 74 months. The survival rates at 1, 3, and 5 years were 78.8%, 62.0% and 54.9% in the HBV group; 86.0%, 64.0%, and 48.6% in the HCV group; and 78.4%, 56.5%, and 45.9% in the NBNC group, respectively. NBNC-HCC has a poorer prognosis than other causes of HCC. Survival was significantly longer in the HBV group with early-stage HCC than in the NBNC group. Furthermore, survival was shorter in patients with early-stage HCC and diabetes mellitus (DM) than in those without DM. Conclusions The etiology of HCC affected clinical characteristics and prognosis to some extent. NBNC-HCC patients showed shorter overall survival than viral-related HCC patients. Additionally, the presence of DM is an additional important prognostic factor in patients with early-stage HCC.