PurposeTo estimate the prevalence of eating disorder symptoms and associated factors in adolescents between 14 and 17 years old.MethodsThe data were obtained from a cross-sectional school-based study with 782 adolescents from public schools in Caxias do Sul, in Rio Grande do Sul, Brazil, in 2016. The Eating Attitudes Test (EAT-26) was used to investigate eating disorder symptoms. The chi-square test and Poisson regression with robust variance were performed to estimate the prevalence ratios and associations between the outcome and the variables of interest.ResultsThe prevalence of eating disorder symptoms was around 56.9% among adolescents and more prevalent in females. A significant association was found between eating disorders and female gender, mothers who did not study or had an incomplete elementary school, and body image dissatisfaction. To adolescents dissatisfied with being overweight, the prevalence was more than three times higher than that observed among those who did not report such dissatisfaction.ConclusionThe presence of eating disorder symptoms was associated with female gender, maternal education, and body image dissatisfaction. The results show the need to identify early signs and symptoms related to changes in eating behavior and non-acceptance of their bodies in a population especially concerned with their physical appearance.