The study aimed to estimate smoking prevalence in Belo Horizonte, Minas Gerais State, Brazil, and related risk factors among adolescents. We used data from the household survey conducted by the Brazilian National Cancer Institute (2002-2003). The following variables were analyzed: demo- graphic data; physical activity; smoking; and alcohol consumption. The study included information on 630 adolescents (15-24 years of age) living in Belo Horizonte. Multivariate logistic regression analyses were carried out, with hierarchical en- try of variables into the model and the generalized estimating equation (GEE) method. Overall smoking prevalence was 11.7%. The following factors were associated with smoking: alcohol consumption (OR = 20.6), older age (OR = 1.2), paternal smoking (OR = 4.0), sibling smoker (OR = 2.5), and best friend smoker (OR = 5.2). Smoking prevalence among adolescents was high, increasing with age and alcohol consumption.