Despite the wide range of breast abnormalities that affect patients in the pediatric and adolescent populations, some conclusions can be drawn. Breast self-examination in the adolescent population is controversial but is recommended for girls who carry the BRCA1 or BRCA2 gene beginning at age 18 to 21 years. All girls with a disorder of breast size or symmetry should be given the opportunity of consultation with a plastic surgeon to discuss reconstructive options. Ultrasound is the most appropriate initial investigation in any adolescent patient with a breast mass owing to the dense nature of breast tissue in this age group. Although it is extremely rare in this population, breast cancer must always be included in the differential diagnosis of a breast mass, particularly in the patient with a prior history of childhood malignancy or chest irradiation.