Aim: To present data on the prevalence of current cannabis use among adolescents and young adults and to identify risk factors that predict problematic cannabis consumption and with which outcome factors this consumption is associated. Methods: The analyses are based on a representative sample of 5,025 Swiss adolescents and young adults aged between 13 to 29 years. The data concerning health and consumer behavior were obtained from subjects in the context of a cannabis monitoring project. Results: Lifetime prevalence amounts to 46 %, whereby men consume significantly more frequently than women. For the 13 to 18 year olds the age of onset for cannabis use averages at 14.7 years. A portion of 13.2 % of all subjects consumes cannabis regularly out of which one third shows problematic consumption patterns. The following factors show a significant association with problematic cannabis consumption: Sex, age of onset and regular tobacco consumption. Conclusions: There is growing evidence for the need for educational, prevention and interventional programs tailored specifically to the 12 to 16 year olds. A valid screening method should be available in order to detect cannabis consumers at risk. The approach of brief intervention is recommended as a cost-effective measure to treat those at risk.