The Society of Surgical Oncology has developed a position statement54 that lists conditions warranting consideration of prophylactic mastectomy (Table 4). It must be stressed that there are no absolute indications for prophylactic mastectomy. The data are limited about the efficacy of prophylactic mastectomy in humans, but recent studies suggest that it results in up to 90% reduction in the risk for breast cancer. Total mastectomy is technically a more definitive procedure, although reported series have had a predominance of patients undergoing subcutaneous, nipple-sparing procedures. Prophylactic mastectomy may improve longevity in BRCA mutation carriers, but this must be balanced against the impact on quality of life. The benefits of prophylactic mastectomy relative to chemoprevention are unclear because there are no prospective randomized studies comparing these two strategies. Contralateral prophylactic mastectomy in patients with a unilateral cancer is unlikely to improve survival, but this approach may be considered for high-risk or difficult-to-observe patients, to facilitate breast reconstruction, and for the psychologic benefits. Patients considering prophylactic mastectomy should be well informed of risk-reduction alternatives and the limitations in the efficacy and cosmetic results of the procedure.