The 5-year experience since the identification of the BRCA1 and BRCA2 genes has shown that genetic evaluation and testing can increase understanding of cancer risks for individuals with a personal or family history of early onset breast cancer and ovarian cancer. However, testing needs to be undertaken in a clinical setting where pretest counseling, including likelihood of identifying a mutation and risks and benefits of the process are provided. Identifying women who carry mutations in either BRCA1 or BRCA2 has implications for prevention, screening and treatment of these cancers.