BACKGROUNDS/AIMS: There are controversies on the role of iron overload in the mechanism of liver injury in nonalcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the prevalence of peripheral iron overload, and to study the presence of HFE mutations (C282Y, H63D, S65C) in a cohort of Korean NAFLD patients. METHODS: 255 patients with NAFLD were included. The patients had been diagnosed as having NAFLD by the criteria of elevated aminotransferase levels, compatible ultrasonographic findings and exclusion of other etiologies. Blood samples were tested for chemistry, iron profile, and mutational analysis for HFE gene (C282Y, H63D, S65C). RESULTS: Of the 255 NAFLD patients, the prevalence of peripheral iron overload was 19.2% according to the cutoff level of transferrin saturation (TS) > 45%, and 3.9% of NAFLD patients were having hyperferritinemia over 400 ng/mL. Hyperferritinemia was significantly associated with elevated serum levels of fasting glucose, AST and TS. We found the presence of H63D mutation, either heterozygote or homozygote, among the NAFLD patients with peripheral iron overload. CONCLUSIONS: The prevalence of peripheral iron overload in the Korean NAFLD patients was not rare, and the presence of H63D mutation among NALFD patients was identified. Further studies on the significance of iron overload or HFE mutation in the pathogenesis of NAFLD are needed.