In this study, breast cancer (n = 23) and benign breast disease (n = 15) patients were evaluated in relation to oxidative stress. The extent of lipid peroxidation was assessed by measuring thiobarbituric acid reactive substances (TBARS) in plasma. Erythrocyte glutathione peroxidase (GSH Px), CuZn speroxide dismutase (CuZn SOD), glutathione (GSH) and plasma vitamin E, cholesterol Fe, Zn, Cu levels were analysed in both groups GSH Px (p < 0.01), vitamin E (p < 0.001), Zn (p < 0.01), Cu (p < 0.05) and cholesterol (p < 0.01) concentrations were found to be significantly increased, TBARS level (p < 0.01) significantly decreased in breast cancer patients in comparison to benign breast disease group.