Information concerning genetic predisposition and the discovery of genes associated with certain cancer risks is changing rapidly. Nurses must keep abreast of these changes so that they can better understand the choices patients have and the consequences of those choices. This article discusses the issues pertincent to women with a genetic predisposition to breast or ovarian cancer, or both. Discoveries in the Human Genome project have already begun to change traditional perspectives on screening, diagnosing, peventing, and treating cancer. These genetic discoveries hold both promise and concern for health care professionals. The promise lies in the precise identification of genetic predisposition to common diseases and the potential to prevent or reduce morbidity and mortality rates. The concern lies in issues of cofidentiality and discrimination: predicting predisposition to incurable illnesses may have substantial negative impact on the person's quality of life and psychosocial integrity.