This chapter addresses the risk factors for ovarian cancer, known and potential prevention strategies, screening methods, early diagnosis, and specific strategies for high-risk populations. The overall lifetime risk in the general population is 1.6%. The actual risk status of women with a family history of ovarian or breast and ovarian cancer can be best determined by a complete genetic history. Genetic counseling for the patient and/or family members includes a comprehensive approach to all issues associated, including quality-of-life and ethical issues, concerns about insurance, and possible options if a diagnosis is made. Women who are known to carry BRCA1 or BRCA2 mutations should be offered a comprehensive approach, including the options of monitoring, chemoprevention, and prophylactic surgery. Preventive measures that have been offered include chemoprevention and prophylactic oophorectomy. There is good evidence that prophylactic oophorectomy reduces risk of breast cancer in women with BRCA1/2 mutations.