Background: Despite the use of currently available drug therapies, the life expectancy of patients with metastasized breast cancer can still only be extended by about 14 to 16 months in comparison to a completely untreated patient population. In light of these figures, and the associated economic costs, all possible means to reduce the incidence of the disease are of great potential importance and must be examined seriously. Prevention: Increased consumption of alcohol is a risk factor for breast cancer. Increased intake of phytoestrogens, dietary fiber, and beta-carotene as well as regular physical activity and normal body weight lower the risk of breast cancer, The increased risk of breast cancer associated with alcohol consumption carl be reduced by adequate intake of folate. The significance of retinoids is at present ambiguous. Conclusion: Effective preventive measures, along with adequate early detection schemes, are the best means of reducing mortality due to breast cancer. Both folate and retinoids deserve to be subjected to further studies. It would also be desirable to supplement currently ongoing adjuvant therapy trials with studies examining the use of folate versus placebo.