The identification of genetic mutations thought to be directly responsible for the development of breast cancer represents a major advance in our understanding of this disease. Mutations in BRCA1 and BRCA2 are thought to be responsible for the majority of inherited breast cancer. Although these mutations account for approximately 5% of breast cancer cases, the identification of these genes will have a profound impact on the way patients and their physicians view breast cancer risk. Genetic testing for BRCA1 and BRCA2 mutations is already available. Interpreting results of genetic tests for these mutations is problematic and the clinical management of women carrying these gene mutations is far from straightforward. The purpose of this paper is to review recent developments in the genetic aspects of breast cancer, including genetic testing, to critically review risk factor modification, and to discuss screening and potential prophylactic measures.