The objectives of this study were to describe the demand for health services by adolescents and to identify associated factors. The study analyzed data from the National School Health Survey 2012 and calculated prevalence rates and 95% confidence intervals (95%CI). Data analysis used age-adjusted logistic regression. Half of all students required health services and the proportion was higher in girls. Factors associated with demand for health services were white skin color, enrollment in private school, maternal schooling ≥ 12 years, sexual activity, injuries, toothache, attempts to maintain, lose, or gain weight, wheezing, appropriate hygiene, and parents knowing what their children did in their free time. The highest demand for health services was mainly by girls, and demand was associated with socio-demographic characteristics, symptoms, and health risk/protective behaviors.