The aim of this study was to determine the effects of catechin and copper supplementations to quail diet on performance, egg quality and lipid peroxidation, plasma 8-hydroxydeoxyguanosine (8-OHdG) concentrations and oxidative status. In this study, 300 quails, 10-week old, were divided into 4 groups with 5 replicates. The dietary treatments were a control diet and a control diet supplemented with 3000 mg/kg of green tea catechins (Cat), 80 mg/kg of copper proteinate (CuP), or 3000 mg/kg of Cat + 80 mg/kg of CuP (combination; Cat + CuP) for 8 weeks. Plasma 8OHdG and enzyme activities did not change. Egg weight and specific gravity of Cat group were lower than that of the control group (p < 0.001). Egg yolk colour increased by dietary catechin (p = 0.001). The MDA concentrations in egg yolk, plasma and tissue decreased by dietary catechin; and kidney MDA concentrations also decreased by all treatments (p < 0.05). Consequently, dietary catechin had a negative effect on egg-specific gravity and a positive effect on egg yolk colour without affecting internal egg quality parameters. However, dietary catechin and copper, without causing DNA damage, reduced lipid peroxidation in egg and organism and has a positive effect on egg lipid peroxidation.