Previous studies have shown that cotinine, a metabolite of nicotine, antagonizes some of the effects of nicotine. One study showed that nicotine eliminates some of the beneficial effects of the nicotine patch in reducing withdrawal symptoms. The purpose of this study was to replicate and extend these findings and examine the effects of various doses of cotinine base compared placebo on withdrawal symptom as well as drug preference among abstinent smokers while using the nicotine patch. We hypothesized that cotinine will reduce the beneficial effects of the nicotine patch in reducing withdrawal symptoms and that placebo will be preferred over cotinine during the forced drug choice period.