Introduction. The fifth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-5) includes a significant revision of Eating Disorders (ED). The objective of this study is to compare the distribution of diagnosis of ED in adolescents according to DSM-VI-TR and DSM-5 criteria. A second objective is to study the psychopathological differences between patients with ED (based on DSM-IV-TR) and those whose diagnosis changed by applying DSM-5 criteria. Methodology. One hundred and one adolescents diagnosed with ED (mean: 14.68 years; SD: 1.46) were evaluated with clinical interviews and scales for eating psychopathology, perfectionism, anxiety, and depression. Results. Applying the DSM-5 criteria led to a significant decrease in the diagnosed cases of Eating Disorders Not Otherwise Specified (EDNOS) (from 34.70/0 to 23.80/0; p<0.001) and to a significant increase in those of anorexia nervosa (AN) (from 58.40/0 to 66.30/0; p<0.001) and of bulimia nervosa (BN) (from 6.90/0 to 8.90/0; p<0.001). No significant psychopathological differences were found between patients diagnosed with AN and BN based on DSM-IV-TR criteria and those newly diagnosed with AN and BN based on DSM-5 criteria. Discussion. Using DSM-5 criteria for adolescents with ED leads to a significant decrease in the frequency of an EDNOS diagnosis. As similar psychopathological characteristics were observed between ED patients diagnosed based on DSM-IV-TR and those who were switched from EDNOS to AN or BN based on DSM-5, we conclude that the new criteria for ED in DSM-5 are valid for an adolescent population.