Oral leukoplakia, a potentially malignant lesion, has been associated with tobacco smoking, but few studies have investigated the influence of different products on lesion prevalence. In the current study 925 healthy male subjects from the Veterans Administration Dental Longitudinal Study were examined for lesion site and prevalence. The participants were grouped according to smoking status: nonsmokers, smokers of cigarettes, cigars, a pipe, cigars plus a pipe, or cigarettes plus another tobacco product. In addition, the amount of product smoked, presence of a removable partial denture, and age were examined to determine their relation to leukoplakia prevalence. The data indicated that cigar smokers had significantly fewer lesions than the other smoker groups and that persons smoking a pipe or a pipe plus cigars had the highest prevalence. Heavy cigarette smokers had significantly more palatal lesions than light to moderate cigarette smokers. While removable partial dentures did not appear to affect lesion prevalence significantly, older smokers, persons of 50 years and above, had a significantly higher prevalence than persons less than 50 years of age.