High incidence of “diseases of affluence” (particularly cancer) motivates numerous research teams to look for causes of morbidity, as well as to search for preventive methods and effective therapeutic measures. The aim of this paper is to present literature on effects of selenium on development of inherited breast cancer in women. The results of national and international research show importance of selenium in prevention and treatment of cancerous diseases, including inherited cancer; they also show the risk of developing cancer in people with hereditary risks and low selenium level. It should be emphasized that the intake of selenium in amounts necessary for proper functioning – given numerous deficiencies (first in the soil, then in food products coming from selenium-deficient soil) – is the first and most important step in prevention and treatment of cancer.