ObjectiveNatural health products and functional foods arefrequently consumed for the prevention and treatmentof many diseases. Flaxseed is one of the functionalfoods with anticancer, antiviral, antibacterial and antifungalproperties. In addition to its beneficial effects,excessive consumption without considering the appropriatedosage can cause toxic effects. In this study,it was planned to investigate the effects of differentamounts of flaxseed consumption on rat liver.Materials and MethodsRats were randomly divided into four groups with 8rats in each groups; control group and experimentalgroups which given flaxseed for 7 days; 1.4, 2.8 and5.6 g/kg/day, respectively. At the end of the experiment,histological, immunohistochemical and biochemicalanalyzes were performed on tissue and bloodsamples.ResultsSerum AST, ALT and ALP values are significantly higherin 5.6 g/kg of flaxseed compared to control group(p values 0.003, 0.012 and 0.009, respectively). Albuminvalues were significantly lower in experimentalgroups compared to the control group (p