Media influence may lead adolescents to internalize patterns of physical beauty, resulting in dissatisfaction with their own bodies when they are unable to match up to these patterns. In the constant search for an ‘ideal body’, adolescents may begin to develop risk behaviors for the development of eating disorders (ED). The object of this study was to analyze the influence of the mass media on body dissatisfaction (BD) and on ED in adolescents, comparing genders. We also analyzed the influence of BD on the risk of developing unsuitable eating behaviors, with risk of ED, comparing genders. A cross-sectional study was carried out with 1011 adolescents: 527 girls and 484 boys. The BMI of each adolescent was determined, and the instruments EAT-26, Sociocultural Attitudes towards Appearance Questionnaire-3 (SATAQ-3), and body shape questionnaire (BSQ), were applied. For statistical analysis, we used Student’s t-test, the chi-square test, Pearson’s correlation test, the odds ratio, and hierarchical multiple linear regression. The influence of the mass media is associated with a greater probability of adolescents presenting BD. An increase in BD is associated with an increased risk of developing ED in adolescents of both genders but is greater in girls than in boys. Furthermore, the influence of the MM and BMI are predictors of BD in both genders; and BD is a predictor of ED risk in both girls and boys.