Background: Free radicals in cigarette smoke may cause oxidative damage to macromolecules, contributing to cardiovascular diseases and cancer. Decreased plasma antioxidant concentrations in smokers may indicate cigarette smoke–related oxidative stress. Objective: We compared the effects on serum antioxidant concentrations in confirmed active smokers with those in nonsmokers, independent of differences in dietary intakes and other covariates. Methods: Serum samples from 60 smokers, and 40 nonsmokers aged 15-60 years were analyzed for ascorbic acid (vitamin C), α-tocopherol (vitamin E), and retinol (vitamin A), by using high performance liquid chromatography (HPLC). The measurement of serum lipid profile, and total lipid peroxidation, oxidized HDL (Ox-HDL) was done as well. Results: Showed significantly lower serum antioxidant vitamins (A, C & E) concentrations in smokers more than in nonsmokers. Smokers had significant elevation in serum malondialdehyde (MDA) (p<0.001) and the percentage of oxidized non high-density lipoprotein (Ox. non HDL %) with a significant reduction in the percentage of oxidized high-density lipoprotein (Ox. HDL %) as compared to the control (p<0.001).Conclusions: These results indicate that cigarette smokers have a significantly lower serum antioxidant status than do unexposed nonsmokers, independent of differences in dietary antioxidant intakes with an increased oxidative stress in smokers' sera. Key Words: Oxidized HDL, ascorbic acid, α-tocopherol , retinol , cigarette smokers.