Developmental breast asymmetry is common in women and may be associated with significant psychological distress. It may be due to deformity of the breast itself (true) or secondary to abnormalities of the underlying torso (apparent). True breast asymmetry may be congenital or acquired. This chapter gives an overview of the aetiology and classification of developmental breast asymmetry and discusses the clinical evaluation of women presenting with breast asymmetry. Congenital breast asymmetry, subdivided into hypoplastic, hyperplastic, and deformational, is discussed. The abnormalities and challenges specific to Poland syndrome and tuberous breast deformity are described. For each subdivision, the surgical techniques available to correct the deformity are reviewed. The limitations of surgery and potential outcomes are discussed.