Oxidative stress arises when there is an imbalance between reactive oxygen species (ROSs) and scavenging capacity of antioxidants, and it can induce and progress many diseases such as breast cancer. The present study was conducted to investigate the status of plasma antioxidative vitamins (E and C) and lipid peroxidation on 50 untreated breast cancer patients and 50 healthy age-matched women. The results revealed that plasma vitamin E and vitamin E adjusted for the sum of cholesterol and triglycerides decreased significantly in patients group (P< 0.05). We could also observe that vitamin E adjusted for lipid was significantly different in various stages of breast cancer. On the other hand, the level of malondialdehyde increased significantly in patients as compared to the controls (P <0.05). There were no significant changes in plasma vitamin C between two groups. According to the findings, attention to the level of plasma antioxidant vitamins and lipid peroxidation is of great importance to promote the level of health in women suffering from breast cancer.