Co-occurring disorders are important to consider in planning smoking cessation interventions with adolescents. We identify factors associated with smoking and predictors for smoking cessation readiness in a group of adolescents in a residential addiction treatment program. Methods: We conducted a chart review study of 400 clinical records of adolescents aged 13 to 18 at a short-term residential addiction treatment program. We examined the relationships of smoking with use of other drugs, psychiatric disorders, and adverse events. Results: The rate of smoking in the total sample was 79%. Smoking onset was positively associated with the onset of alcohol and other drugs of abuse but followed the onset of cannabis use for over half the sample. Heavy smoking, defined as smoking 10 cigarettes per day on average, was correlated with cocaine and opiate addiction. Over half of the sample (56%) was precontemplative about smoking cessation, whereas 30% were in the contemplative stage (ready to stop in 6 months); 12% were in preparation stage (ready to stop in 30 days); and 2% reported that they already had stopped. Heavy smoking was associated with being precontemplative as was earlier onset of drinking relative to smoking and bipolar diagnosis. Conclusions: Smoking is common in adolescents seeking drug and alcohol treatment and is correlated with the onset and progression of other drug use. Increasing motivation for change and addressing the interface of nicotine, other drugs, and mental health are important for smoking cessation interventions for adolescents in residential addiction treatment settings.