To estimate the amount of misuse of and dependence on nicotine gum in an over-the-counter (OTC) setting, we conducted two telephone surveys of smokers recruited by newspaper ads. Study 1 surveyed 266 U.S. ever-smokers using OTC gum to determine the percentage who used the gum for noncessation reasons or used gum and cigarettes concurrently. In Study 1, 6% initially purchased nicotine gum to reduce smoking and 1% to avoid smoking restrictions. At the time of interview, 35% chewed gum and smoked cigarettes concurrently with a mean of six cigarettes per day and 15 mg/day of nicotine from gum. Among long-term users (>/=90 days), 20% attributed their use to addiction. To determine what proportion of those reporting addiction would meet DSM-IV or ICD-10 criteria for dependence, Study 2 surveyed 100 current and ex-smokers who reported addiction to OTC nicotine gum. In these gum users, 66% met DSM-IV and 74% met ICD-10 criteria for dependence. Combining the results of Studies 1 and 2 with other data suggests very few gum users develop dependence on the gum. We conclude (a) very few people use nicotine gum for noncessation reasons, (b) concurrent use of gum and cigarettes is common but involves a small number of cigarettes and pieces of gum per day, and (c) the incidence of dependence on OTC nicotine gum is very small.