In women diagnosed with breast cancer and testing positive for a BRCA1/2 mutation, decisions as to whether to undergo prophylactic risk-reduction surgery may differ from those women who test positive in a presymptomatic phase. Eighty-four women were identified who had undergone genetic testing at the time of breast cancer diagnosis. The study group consisted of 46 of these women who had initially undergone breast-conserving surgery. Eight patients (17.4%) tested positive for a mutation. Seven of the eight underwent bilateral prophylactic mastectomy prior to receiving radiation therapy. The only patient not undergoing bilateral mastectomy was awaiting liver transplant. Women who are candidates for breast-conserving surgery and who test positive for a breast cancer gene mutation choose mastectomy over surveillance.