Objective: Although there are various studies concerning the prevalence of cigarette, alcohol and drug use among adolescents in Turkey, it is difficult to compare the results among different regions because of the different methods used in these studies. The aim of the present study was to investigate substance use among second year high school students in 15 different cities.

Method: The research was conducted in Adana, Ankara, Antalya, Denizli, Diyarbakir, Eskisehir, Erzurum, Istanbul, Izmir, Kocaeli, Malatya, Mugla, Sivas, Trabzon and Van. A total of 20245 questionnaire forms were given to second -year high school students between the ages 15 and 17. The number of valid questionnaires is 18599.

Results: It was found that while the rate of having smoked at least one cigarette during one’s lifetime was 63.9%, the rate of smoking every day was 22%. 17.3% of students stated that during the past month they had drunk at least one alcoholic beverage and 9% stated that they drink alcoholic beverages once a week. The rate of having used a substance at least once in one’s lifetime was 3.6% for cannabis, 8.6% for volatile substances, and 3.3% for other substances.