BACKGROUND: Adolescent reduction mammaplasty remains controversial because of concerns of postoperative breast growth, complications, and the effect on well-being. The authors sought to prospectively quantify early and late complications following reduction mammaplasty in adolescents and young women, and examine the intersection of surgical complications and postoperative health-related quality of life. METHODS: From 2008 to 2017, female patients aged 12 to 21 years undergoing reduction mammaplasty were asked to complete the 36-Item Short-Form Health Survey (version 2), the Rosenberg Self-Esteem Scale, the Breast-Related Symptoms Questionnaire, and the Eating-Attitudes Test-26 preoperatively and postoperatively at 6 months and 1, 3, 5, and 7 years. Clinical evaluations using standardized forms assessed baseline and postoperative symptomatology, complications, and surgical outcomes. RESULTS: In the authors' sample of 512 participants, the most common complications included hypertrophic scarring (20.0 percent) and altered sensation of the nipple (8.4 percent) or breast (7.8 percent). Patient age, body mass index category, and amount of tissue resected did not significantly increase the odds of developing a complication. Significant postoperative improvements on the Rosenberg Self-Esteem Scale, the Breast-Related Symptoms Questionnaire, the Eating-Attitudes Test-26, and in all 36-Item Short-Form Health Survey domains (i.e., physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health) were largely seen irrespective of whether complications occurred. CONCLUSIONS: Although complications following reduction mammaplasty were common, the vast majority were minor. Patients had significant postoperative improvements in their physical and psychosocial well-being regardless of whether they experienced a complication. Concerns for potential complication, especially in younger and overweight or obese patients, should not preclude otherwise healthy adolescents and young women from the benefits of reduction mammaplasty. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.