The assessment of nutritional status of adolescents is not an easy task because it should take into account sex, age, weight, stature and sexual maturation of the adolescents. In addition, an adequate classification should also be related to subsequent health-related outcomes during adult life. On the other side, screening for overweight and underweight among adolescents is highly desirable since nutritional status during adolescence correlates with adult body habitus. The objective of this study was to propose a classification for screening the nutritional status of Brazilian adolescents based on the body mass index (kg/m2) provided by the Pesquisa Nacional sobre Saúde e Nutrição-PNSN, a national survey of the Brazilian population carried out on 1989. We defined as cutoff the 10th and 90th percentile of the body mass index distribution and the 10th percentile for stature.