Selected high-risk women without breast cancer choose to undergo bilateral prophylactic mastectomy (BPM) to reduce their risk of developing the disease. Several studies have reported that BPM significantly reduces, but does not eliminate, breast cancer risk. Few studies have reported rates or trends of BPM use. Patients with unilateral breast cancer are at increased risk for developing cancer in the normal contralateral breast. Some breast cancer patients choose contralateral prophylactic mastectomy (CPM) to prevent cancer in the contralateral breast. The risk of contralateral breast cancer is significantly reduced after CPM. Recent studies reported that CPM rates have markedly increased in recent years in the United States. Alternatives to CPM include surveillance with clinical breast examination, mammography, and, potentially, breast MRI. Endocrine therapy with tamoxifen or aromatase inhibitors significantly reduces the risk of contralateral breast cancer and may be more acceptable than CPM for some patients.