BACKGROUND: Hepatic steatosis due to estrogen therapyincreases the activity of inflammatory markers, particularly theactivity of TNFα which in turn induces more lipogenesis.Omega-3 fatty acids are among the negative regulators of hepaticlipogenesis. OBJECTIVES: In this research, the preventive effectof omega-3 fatty acids on estrogen-induced steatosis in rats wasevaluated. METHODS:2 mg/kg. BW/SC of 17α-ethiny-lestrasdiolwere injected into 25 female wistar rats in 5 equal groups(excluding the control group) over 10 consecutive days.Simultaneously, 3 of estradiol-treated groups were orally given250, 500, and 1000 mg/kg. BW omega-3 fatty acids, respectively.At the end of the experiment, plasma ALT, AST, and TNFαlevel were determined. Histopathological changes in the liverwere also identified by the evaluation of samples stained withH&amp;E and Oil Red O. RESULTS: The histological findingsrevealed hepatic microvesicular steatosis and fat deposit inethinylestradiol and, to a lesser extent, in the 250 mg/kg BWomega-3 fatty acids groups. The plasma levels of AST, ALT, andTNFα significantly increased in the ethinylestradiol groupcompared to the control (p<0.05) and 1000 mg/kg. B.W omega-3 group. Omega-3 fatty acids reduced these parameters incomparison to the estradiol group (p<0.05). CONCLUSIONS: Itwas concluded that 1000mg/kg.BW of omega-3 protects theliver against steatotic injuries.