The study aimed to determine associations between diet’s composition and serum antioxidant potential in 29 women aged 19-22 years. The participants completed self-report questionnaires concerning health condition, body measures, dietary habits and supplements taken, and 3-day detailed diet records. Fasting blood samples were collected to assess total antioxidant status (TAS) and ferric reducing antioxidant power (FRAP) in the serum. The women reported good health condition and lean body. The data concerning the TAS and FRAP methods demonstrated that the antioxidant potential was negatively correlated with saturated fat intake (r=-0.515 and r=-0.527, respectively), but not related to the intakes of protein, carbohydrate, mono- and polyunsaturated fats, cholesterol and antioxidant vitamins (vitamin C, β-carotene, α-tocopherol). The TAS antioxidant activity of the serum was significantly lower in the top vs. bottom quartile of the saturated fat intake, which corresponds to a consumption of at least 29 g saturated fat vs. intake below 19.7 g. The FRAP value in the highest quartile of the saturated fat intake was also reduced and close to significance. This study shows that the studied group of young women exposed to diets, which contained high amounts of saturated fat, are prone to risk of oxidative stress.