Prevalence and Correlates of Smoking Behavior Among Patients with Substance Use Disorders in a Specialized Adolescent Psychiatric Outpatient Clinic Abstract: Objective: Germany lacks recent data on the incidence and severity of tobacco use and tobacco use disorders (TUD) in high-risk populations, especially among adolescent outpatients with substance use disorders (SUDs). Method: We collected data from N = 134 adolescents in a specialized SUD outpatient unit for adolescent psychiatric patients using structured interviews (consumption and disorder symptoms) and a sociodemographic caregiver questionnaire (education, subjective financial status, and housing status). Descriptive data and linear regression models present possible associations between consumption, disorder diagnoses, and social demographics. Results: There were high 30-day prevalence rates for smoking (95 %), daily smoking (79 %), heavy or very heavy smoking (61 % and 23 % among smokers, respectively), and past-year TUD (77 %). Daily average consumption of M = 11.0 cigarettes was associated with a lower age at first use (M = 12.6 years), which in turn was lower for those with a lower level of education and a worse financial situation. Conclusions: The extremely high prevalence of smoking, early onset of use, and high rate of TUD highlight the urgent need for tailored smoking cessation programs for adolescents with SUD.