Data from the European School Survey Project on Alcohol and other Drugs have shown that adolescent substance use is a growing problem in western and particularly Eastern European countries. This paper describes the development, implementation and results of the Icelandic Model of Adolescent Substance Use Prevention. The Icelandic Model is a theoretically grounded, evidence-based approach to community adolescent substance use prevention that has grown out of collaboration between policy makers, behavioural scientists, field-based practitioners and community residents in Iceland. The intervention focuses on reducing known risk factors for substance use, while strengthening a broad range of parental, school and community protective factors. Annual cross-sectional surveys demonstrate the impact of the intervention on substance use among the population of 14- to 16-year-old Icelandic adolescents. The annual data from two cohorts of over 7000 adolescents (>81% response rate) show that the proportions of those who reported being drunk during the last 30 days, smoking one cigarette or more per day and having tried hashish once all declined steadily from 1997 to 2007. The proportions of adolescents who reported spending time with their parents and that their parents knew with whom they were spending their time increased substantially. Other community protective factors also showed positive changes. Although these data suggest that this adolescent substance use prevention approach successfully strengthened a broad range of parental, school and community protective factors, the evidence of its impact on reducing substance use needs to be considered in light of the correlational data on which these observations are based.