Several studies have shown high levels of interest in smoking cessation among methadone maintained heroin users, yet little is known about how to intervene most effectively with this population. The present study examined data from a large controlled trial of behavioral therapy in combination with nicotine replacement to find predictors of smoking cessation among the methadone maintained. Logistic regression analyses showed that less nicotine dependence, as measured by the Fägerstrom Test of Nicotine Dependence, and greater age were associated with higher rates of tobacco cessation. Greater opiate use, fewer nicotine patches used, and any tobacco smoking during weeks 2 and 3 of the intervention significantly negatively predicted smoking cessation outcomes.