Prevalence of smokeless tobacco use is reported for adults aged 21 years and older in the Adult Use of Tobacco Surveys, 1964-1986. Data from the 1986 survey on prevalence, beliefs, ages of initiation, and demographic correlates of use by males aged 17 years and older are also reported. The prevalence of smokeless tobacco use declined slightly among persons aged 21 and older between 1966 and 1986. However, 5.2% of the males aged 17 and older used smokeless tobacco in 1986, and prevalence was highest among those 17 to 19 years old (8.2%). The median age of initiation for both products was 19 years. Smokeless tobacco use was most common among white men who were 1) living in the southeastern United States, 2) unemployed, and 3) in blue-collar or service/labor employment. Most users (77.4%) and nonusers (83.4%) believe that smokeless tobacco is a health hazard. Many current users (39.1%) had attempted to quit. Some current (6.4%) and former smokers (7.0%) have used smokeless tobacco as an aid to smoking cessation. National survey data such as these permit the identification of high-risk groups, so that interventions against smokeless tobacco use may be specifically targeted.