Nicotine addiction is one of the most prevalent addictive behaviors worldwide. According to the World Health Organization (WHO), 1.3 billion men, women and children worldwide are smokers. In spite of increased awareness and action on the part of both governments and individuals, tobacco continues to be the leading cause of preventable disease and death in the United States, as well as in many other countries. According to WHO, there are nearly 5 million tobacco-related deaths worldwide each year and nearly half of the smokers in the world today will die as a result of their addiction. For individuals who are motivated to quit smoking, a combination of pharmacotherapy and behavioral therapy has been shown to be most effective in controlling the symptoms of nicotine withdrawal. Drugs marketed as smoking cessation aids include nicotine replacement therapy (NRT) and sustained-release bupropion hydrochloride. New drugs in development are directed to targets including nicotinic acetylcholine receptors, cannabinoid receptors, dopamine receptors and opioid receptors. Several therapeutic vaccines are also in the pipeline.