The main purpose of the ESPAD project was to collect comparable data on alcohol, tobacco and drug use among students born in 1979 in as many European countries as possible. The studies were designed to be conducted as school surveys by researchers in each participating country, during the same period of time, with a common methodology. By doing this, it was hoped that comprehensive and comparable data on alcohol, tobacco and drug use among 15–16 year old students would be available for the first time on a European level.