Transdermal nicotine patches have been successfully introduced as a safe and powerful aid to smoking cessation; this has contributed to the rising interest in additional therapeutic applications for nicotine and synthetic nicotinic agonists. Nicotine and nicotinic agonists may have a therapeutic potential for a variety of disorders, including Alzheimer's and Parkinson's diseases, depression, attention deficit disorder, Tourette's syndrome and ulcerative colitis. These interests are partially fuelled by the urgent need of the tobacco industry to find new niches for nicotine in a world bound eventually to retire from cigarette smoking. At the same time, there is an increased interest in developing drugs for fighting obesity, a growing affliction of industrialised nations. This review presents data on the potential of nicotine, and in particular synthetic nicotinic agonists, for controlling body weight. Nicotinic agonists may become relatively safe, effective and inexpensive alternatives for several optional drugs currently being developed for treating human obesity, including beta-3-adrenergic agonists, leptin and its agonists, and neuropeptide Y antagonists.