LDL-lipids peroxidation is an important step in LDL atherogenicity. Tobacco smoke, promotes oxidative stress and reduces LDL-alfa tocoferol content and plasmatic vitamin C concentration. The objective of this double-blind randomized study was to assess the effect of vitamins E and C combined administration, on oxidative susceptibility of LDL isolated from 20 smokers and 10 non-smokers healthy volunteers who received placebo for 15 days and then concomitantly received 400 mg/d vitamin E and 1000 mg/d vitamin C for 30 days. At the end of placebo administration of and vitamins E and C combination; plasma total cholesterol, LDL-C and HDL-C values did not change significantly (p>0.05), plasma triglycerides increased significantly within a normal accepted range (p<0.05) and LDL oxidation susceptibility in smokers decreased by 41,3% and in non-smokers by 54,4% (p<0.05 vs placebo). In conclusion, simultaneous administration of vitamins E and C exerts an important antioxidant effect on LDL-lipids peroxidation. This effect could operate as an attenuating factor of the increased atherogenesis commonly observed in smoker subjects.