ObjectiveAnorexia nervosa and borderline personality disorder are often associated and share some core elements, including emotional dysregulation and affective instability. Nevertheless, the association of these two conditions in adolescence is still little studied.MethodThe present study aims at investigating, through a multidimensional assessment, the psychopathological characteristics of adolescents affected by anorexia nervosa in comorbidity with borderline personality disorder on a sample of 127 female adolescents, through the comparison with adolescents with borderline personality disorders and adolescents with anorexia nervosa. All participants completed a validated psychometric battery assessing alexithymia (Toronto Alexithymia Scale‐20), depression (Children's Depression Inventory), psychological symptoms (Symptom Checklist‐90–Revised) and psychological symptoms relevant in eating disorders (Eating Disorders Inventory‐3).ResultsAdolescents with anorexia nervosa in comorbidity with borderline personality disorder show intermediate features between the two disorders individually in the general psychopathological profile, but a peculiar psychological profile regarding the eating symptomatology, with worse features compared to adolescents with the sole anorexia nervosa.ConclusionsResults suggest a peculiar clinical and psychopatological endophenotype in adolescents with anorexia nervosa in comorbidity with borderline personality disorders, indicating the need to define specific and tailored treatment for this population.