Because of the lack of effective alternatives and the simplicity of the procedure, prophylactic oophorectomy is viewed as the best available tool for reducing the individual risk of ovarian cancer. The genetics of hereditary ovarian cancer are described in this chapter and a careful risk-versus-benefit assessment is provided with respect to two populations of patients that appear suitable candidates for this procedure. These include patients with increased risk of developing ovarian cancer due to hereditary genetic predisposition, in which the lifetime risk of ovarian cancer may be as high as 16-65%, depending on the penetrance of the germ-line mutation. Additionally, routine salpingo-oophorectomy in patients over 40 years undergoing scheduled gynaecological surgery or colorectal surgery might reduce the overall incidence of ovarian cancer by as much as 5% in the general population.