This report presents the key results of the 2015 ESPAD surveys that have been conducted in 35 countries: Albania, Austria, Belgium (Flanders), Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, the Faroes, Finland, the former Yugoslav Republic of Macedonia, France, Georgia, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Malta, Moldova, Monaco, Montenegro, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Sweden and Ukraine. Firstly, the present report provides information on the availability of substances, early onset of substance use and prevalence estimates of substance use (cigarettes, alcohol, cannabis, illicit drugs, inhalants, new psychoactive substances and pharmaceuticals). The descriptive information also includes indicators of intensive substance use and prevalence estimates of internet use, gaming and gambling by country and gender. Secondly, overall ESPAD trends between 1995 and 2015 are presented. For selected indicators, ESPAD trends are shown based on data from 25 countries that participated in at least four (including the 2015 data collection) of the six surveys. Finally, for some indicators, country-specific trends are shown. For comparative reasons the tables of the 2015 ESPAD results contain, in addition to country-specific estimates, an unweighted average across all participating countries as well as prevalence estimates for Spain and the United States, which are both non-ESPAD countries. Data for Spain come from the Spanish national school survey collected between November 2014 and April 2015 (Spanish Observatory on Drugs and Drug Addiction, 2016a, b), and the US data stem from the 2015 ‘Monitoring the future’ project (Johnston et al., 2016). The instruments used in the Spanish and US surveys overlap to a large degree with the ESPAD questionnaire, and the methodology used in all three surveys allows for rough comparisons across the countries. Many of the ESPAD questions were originally taken from the ‘Monitoring the future’ study.