['Steatosis is an increasingly common problem worldwide, accompanying increasing obesity. Recently, it has been suggested that oxidative stress plays an important role in development of fatty liver disease. We carried out an epidemiological study to clarify the role of oxidative stress and antioxidative activity in steatosis.', 'This study was conducted with 184 male workers who had received their annual health checkup. Steatosis was confirmed using ultrasonography. Oxidative stress and antioxidative activity were assessed using the dROM test and the BAP test, respectively.', 'Steatosis was confirmed in 59 subjects (29.7%) by ultrasonography. There was no significant difference between cases and controls in BAP levels (2229.0 μmol/L vs. 2194.3μmol/L, p = 0.83). The steatosis group showed significantly lower dROM levels than the control group (332.7 U. CARR vs. 316.8 U. CARR, p < 0.05). In addition, we carried out logistic regression analysis to assess the combination between dROM levels and BAP levels. Subjects with high dROM levels and high BAP levels had 74% lower risk for steatosis than subjects with low dROM levels and high BAP levels.'] Are moderate oxidative stress and high antioxidative activity associated with steatosis in Japanese males?