Smoking has been established as an important risk factor for periodontal disease and tooth loss. The purpose of this study was a prospective evaluation of the effects of smoking on dental care utilization and its costs, based on data from 5712 males aged 20-59 yrs. Age, dental health behavior, and history of diabetes were adjusted in a multivariate analysis. Current smokers accrued 14% higher dental care costs than never-smokers over a five-year period. This difference in annual dental care costs was mainly attributable to the increased percentage of participants in the 'higher dental care cost' category among current smokers. There was no clear trend identified for the dose-dependent effects of smoking on dental care utilization and its costs. Past smokers incurred lower dental care costs compared with current smokers. Smoking may have played a key role in the increment of dental care utilization and its costs via deterioration in oral conditions.