This study researched the prevalence of psychoactive drugs, and their use without the guidance of a professional of health, by teenagers attending at the high school of public and private schools in the countryside of Rio Grande do Sul. 178 participants, boys and girls aged from 14 to 19 years old, were studied. The instrument used was a self responding questionnaire of assessment of CEBRID (Centro Brasileiro de Informações sobre Drogas Psicotrópicas), which was adapted, and with 15 specific questions. The results showed that the drugs most used are: cannabis (10%), amphetamines (7.3%), anxiolytics (3.4%), solvents (2.2%), anabolic-androgenic steroids (1.7%), cocaine (1.7%), and hallucinogens (1.1%). The relevant rate of the users of Cannabis, as well as the drug universe spreads facilities, leads to the necessity of new researches and intervention programs adequated to this population.