This review summarizes evidence pertaining to the role of nicotine medications in smoking cessation and focuses particularly on evaluating evidence of the impact that nicotine replacement therapies (NRT) have had on altering population trends in smoking behavior. Accumulated evidence from controlled clinical trials has demonstrated that available forms of NRT (e.g., gum, transdermal patch, nasal spray, inhaler, and lozenge) increase quit rates compared with placebos by 50%-100%. However, despite the positive results from these studies, fewer than one in five smokers making a quit attempt do so with the benefit of NRT. Because not enough smokers are using NRT, the availability of NRT has not had a measurable impact on influencing population trends in smoking behavior. Among the factors contributing to the low utilization of nicotine medications are the inadequacies of the current dosage strengths and formulations of existing medications, smokers' perceptions of the high cost of the drugs, and concerns that many smokers have about safety and efficacy of nicotine medications.