Not On Tobacco (N-O-T) is a school-based smoking cessation program designed for youth ages 14 to 19 who are daily smokers. N-O-T is based on social cognitive theory and incorporates training in self-management and stimulus control; social skills and social influence; stress management; relapse prevention; and techniques to manage nicotine withdrawal, weight, and family and peer pressure. The program consists of 50-minute group sessions conducted weekly for 10 consecutive weeks, plus four optional booster sessions. The sessions are delivered in gender-specific groups of 10-12 teens by same-gender facilitators. N-O-T can be implemented by schools or other community organizations using teachers, school nurses, counselors, and other staff and volunteers who are trained to facilitate group sessions.