Objective: To assess the prevalence of and factors associated with smoking experimentation among adolescents. Methods: Cross-sectional study, using a specific questionnaire to interview 2,883 students from 7th to 10th grade in schools located in the urban area of the city of Cuiabá, in the state of Mato Grosso, Brazil. Prevalence was estimated, and the principal factors related to cigarette experimentation were analyzed. Subsequently, a hierarchical logistic model was used to describe the chances of cigarette experimentation related to the variables being investigated. Results: The prevalence of cigarette experimentation was 30.2%. In the final model of the analysis, the main variables related to cigarette experimentation were low maternal level of education (OR = 2.44; 95% CI: 1.72-3.47); low socioeconomic level (OR = 1.39; 95% CI: 1.01-1.93); studying in a public school (OR = 1.56; 95% CI: 1.22-2.00); being in 10th grade (OR = 3.45; 95% CI: 2.63-4.54); attending school in the evening (OR = 2.44; 95% CI: 1.85-3.22); having divorced parents (OR = 1.23; 95% CI: 1.02-1.49); having been held back for one school year (OR = 2.17; 95% CI: 1.78-2.70); having friends who smoke (OR = 3.75; 95% CI: 2.99-4.70) having a sibling who smokes (OR = 2.44; 95% CI: 1.82-3.27); and being older (age 17-19 years) (OR = 2.44; 95% CI: 1.39-4.17). Conclusions: A high proportion of adolescents have experimented with smoking. After adjusting for confounding variables, the factors most strongly associated with cigarette experimentation were maternal level of education, age of the adolescent, attending school in the evening, having been held back for one school year and having a sibling who smokes. Preventive measures must be directed at adolescents in schools in order to control smoking.

Keywords: Smoking; Adolescent; Students; Risk factors.