This study examines the level of body satisfaction in adolescents, and its association with age, sex and body mass index. A non-clinical group was made up of 935 adolescents (484 boys and 451 girls), aged between 10 and 18 years. The body image was assessed by the Body Dissatisfaction scale within the Eating Disorder Inventory (Garner, 1998, 2004) and by the indirect indicator Ideal Body Mass Index. The results showed that the Body Mass Index is an important covariable in the study of body dissatisfaction. Body dissatisfaction mean values increased in the female sample. The males' values did not change throughout adolescence.