Genetic testing for disease susceptibility has the potential to revolutionize health care by allowing for individually tailored disease prevention strategies. To achieve this promise, patients and physicians must use the information obtained through genetic testing to make medical decisions that are consistent with patient preferences and that lead to reduced disease morbidity and mortality. However, decisions associated with genetic testing can be complex. In this article, the authors review decision making associated with genetic testing and the medical management of hereditary breast-ovarian cancer susceptibility. They focus on decisions regarding BRCA1/2 testing and prophylactic surgery among BRCA1 and BRCA2 mutation carriers. They highlight the role of patient preferences and decision support in this population. The studies reviewed indicate that although patients' preferences do predict genetic testing and management decisions, other factors also influence their decision making. In particular, the authors discuss the role of anxiety and worry in relation to testing and surgery decisions.