Is Female Genital Cosmetic Surgery for an adolescent with Body Dysmorphic Disorder ever ethically justified? Cosmetic genital surgery for adolescent girls is one of the most ethically controversial forms of cosmetic surgery and Body Dysmorphic Disorder is typically seen as a contraindication for cosmetic surgery. Two key ethical concerns are that Body Dysmorphic Disorder undermines whatever capacity for autonomy the adolescent has; and even if there is valid parental consent, the presence of Body Dysmorphic Disorder means that cosmetic surgery will fail in its aims. In this article, we challenge, in an evidence-based way, the standard view that Body Dysmorphic Disorder is a contraindication for genital cosmetic surgery in adolescents. Our argument gathers together and unifies a substantial amount of disparate research in the context of an ethical argument. We focus on empirical questions about benefit and harm, because these are ethically significant. Answers to these questions affect the answer to the ethical question. We question the claim that there would be no benefit from surgery in this situation, and we consider possible harms that might be done if treatment is refused. For an adolescent with Body Dysmorphic Disorder, the most important thing may be to avoid harm. We find ourselves arguing for the ethical justifiability of cosmetic labioplasty for an adolescent with Body Dysmorphic Disorder, even though we recognize that it is a counter intuitive position. We explain how we reached our conclusion.