BACKGROUND: Rates of smoking among adolescents with psychiatric comorbidity are high, despite the well-known health risks. The current longitudinal study examined patterns of quitting behavior in adolescent smokers with psychiatric comorbidity. METHODS: The study evaluated 191 inpatient adolescents who had been enrolled in a randomized controlled trial of motivational interviewing versus brief advice for smoking cessation, and assessed their intentions to quit smoking. RESULTS: Rates of quit attempts at post-hospital, 1-month, and 6-month assessments were 23%, 17%, and 17%, respectively. Adolescents who reported an intention to quit smoking (43%) were significantly more likely to report a quit attempt, regardless of psychiatric symptoms, cognitive factors, or substance use. CONCLUSIONS: Intention to quit smoking appears to translate to substantial quit behavior, even in a high-risk adolescent population that may otherwise be viewed as uninterested in quitting, suggesting the need to proactively connect this population with adequate services and follow-up support. (Am J Addict 2013;XX:1-6).