Breast cancer is the commonest type of cancer among women in industrialized countries. The incidence of breast cancer increases rapidly with age during the reproductive years and then increases at a slower rate after about age 50 years, the average age of menopause. Preventive programmes and early diagnosis identify those risk factors associated to breast cancer, not all determined. Some of these risk factors act through hormonal mechanisms or are promoted by endocrine conditions. Many epidemiological studies have been carried out to identify risk factors for breast cancer. Breast cancer is a progressive neoplasia, that if diagnosed at an early stage has a higher rate of therapeutic success. It is of vital importance to precociously diagnose the tumor before reaching the palpable stage. This can be carried out by screening that allows the precocious diagnosis of hidden neoplasia and not clinically evident in asymptomatic women. Annual mammography and clinical examination should be carried out after 40 years of age in low risk women, who would be informed about its benefits, limitations and potential risks associated to regular screening. All women should be aware of the fact that the incidence rate is lower in younger women and increases with age. Mammographic screening of elderly women should be personalized to assure quality and life expectation. Healthy women can benefit from possible treatment and so should continue to undergo annual screening. On the other hand, if life expectation is limited to less than 3 years, because of functional limitations associated to multiple pathologies, annual screening is not advisable. Chronological age must not limit screening. Women that are considered at high risk for breast cancer can start screening at an earlier age, shorter screening intervals, and undergo other forms of screening apart from the physical examination and mammography (for example magnetic resonance). It is very important to identify those women at high risk. Future research will included the possibility to diagnose aggressive tumors and not, identify the ideal screening methods, to be aware of the impact of hormonal therapy on the mammary density, to determine the role of physical examination for diagnosis of cancer and to increase the efficiency of mammography.