Breast asymmetry is one of the most frequent deformities which require mastoplasty. Although the recommended surgical treatment is after puberty, quite often the problem comes from childhood. The asymmetry is not only on the volume of the mammary gland but also on skin structures and nipple-areolar regions. A classification of breast deformities addresses the diverse pathology, emphasizing the appropriate age for surgery. It is classified as congenital and acquired. Congenital asymmetry may present with or without chest deformity, with or without nipple deformity. Acquired deformities are caused by traumatic or iatrogenic. Each patient must be treated according to peculiar deformity on each breast. For this reason, clinical evaluation and surgical planning are important steps before the operation. The surgical treatment may be performed under local anesthesia combined with intravenous sedation under the care of an anesthesiologist. In some patients, reduction mastoplasty is performed on one side and breast augmentation with silicone prosthesis on the opposite side. Other patients may be treated with asymmetric mastoplasty.