Antioxidant compounds have been reported to play a beneficial role in the etiology of several chronic diseases. To examine the effects of tobacco smoking and demographic factors on the plasma levels of alpha-carotene, beta-carotene, lycopene, beta-cryptoxanthin, and jointly, lutein-zeaxanthin, we have conducted a cross-sectional study in the context of the Greek segment of the European Prospective Investigation into Cancer and nutrition (EPIC). A random sample of 45 men and 68 women, aged 30-82 years, from the Greek EPIC cohort of 27953 volunteers, provided fasting blood samples and completed an interviewer-administered questionnaire on lifestyle factors. Data were analyzed using linear regression models with the studied vitamin plasma levels as dependent variables, and tobacco smoking and demographic factors as independent variables. Older persons had significantly lower alpha-carotene levels and significantly higher lutein-zeaxanthin levels, whereas females in comparison to males had significantly higher levels of alpha-carotene and perhaps beta-carotene. Tobacco smoking tended to reduce levels of all carotenoids studied and the reduction was statistically significant with respect to beta-cryptoxanthin and beta-carotene, whereas it was of borderline significance with respect to alpha-carotene.