Objectives: To assess whether current smokers eat differently than never smokers and the relation of smoking cessation to dietary change. Design: Population-based survey from 1993 ± 1997. Setting: The Bus Sante  2000, epidemiologic observatory of Geneva, Switzerland. Subjects: A representative sample of 2301 men and 2306 women resident of Geneva, Switzerland. Results: In both genders, compared to never smokers, current heavy smokers ( ! 20 cigarettesad) consumed daily less total vegetables proteins (P`0.03), carbohydrates (P`0.0001), saccharose (P`0.01), ®bers (P`0.0001), beta-carotene (P`0.001), fruit (P`0.0001) and vegetables (P`0.04), but they drank more alcohol (P`0.0001) and more coffee (P`0.005). In addition, female current smokers ate less energy (P`0.4), complex carbohydrates (P`0.002), cereals (P`0.003), vegetables (P`0.0001) and less iron (P`0.02). The diet of ex-smokers tended to become more similar to that of never smokers. When longer duration of smoking cessation increased, the consumption of total carbohydrates and complex carbohydrates increased (P`0.01 and P`0.06), and alcohol decreased (P`0.07) in both genders. Conclusions: As in other Western countries, the diet of Swiss smokers appears less healthy than that of never smokers in both men and women, while smoking cessation has bene®cial aspect on the quality of the diet. Current smoking appears to have an even stronger effect on the diet of women than on the diet of men. Sponsorship: Swiss National Fund for Scienti®c Research (Grants No 32.31.326.91,