Substance use among young people is an important issue for educational, social and medical providers. More than 75% young people have had a medical visit in the last 12 months, making primary care settings ideal for screening and early intervention programs. The prevalence of substance misuse was assessed with the DEP-ADO screen test among young patients attending the primary care consultation of Geneva University Hospitals. The screen was well accepted by both patients and providers and only took about 10 minutes to complete. One in five screened positive for problematic substance use, supporting the current guidelines recommending annual screening for substance misuse in adolescent primary care outpatients.