Five percent to 10% of all women who develop breast cancer carry a hereditary mutation in the genes BRCA1 or BRCA2. Genetic testing is now clinically available, and the results of such testing can dramatically alter a patient's risks for an ipsilateral or contralateral primary breast cancer and ovarian cancer. Therefore, genetic testing will become integral in tailoring surveillance, chemoprevention, and surgical management plans for patients at risk for hereditary cancer syndromes. Such results will also impact the cancer risks for the patient's nuclear and extended family members. Surgeons will play a pivotal role in eliciting personal and family histories from patients, determining which of those histories is suggestive of a germline mutation, facilitating referrals for genetic counseling and testing, and incorporating the results of genetic testing into the patient's short- and long-term management plans.