Breast cancer is the most common malignant disease in women under 70, and the most common cause of death in those under 50. Causal prophylaxis is unknown. Only early diagnosis prior to the onset of lymphogenic or hematogenic metastasization improves the prognosis. Since the early nineteen-sixties, large-scale studies have shown that screening mammography can reduce mortality. Furthermore, early diagnosis enables breast-conserving treatment in up to 70% of cases. Disadvantages of screening mammography currently under discussion are the radiation burden, the number of false-positive diagnoses prompting biopsy and incurring costs. In Germany, the cost of screening mammography in women with no relevant history or clinical symptoms is not borne by the state-affiliated health insurance carriers. Currently, ongoing pilot projects are investigating quality-controlled early diagnosis with mammography.