The purpose of this review is to examine the literature to determine what epidemiologic and experimental evidence exists that either supports or denies a role for iron in the etiology of breast cancer, paying particular attention to the dietary heme iron source of red meat. The importance of red meat as a dietary source of iron and the relationship between iron and oxidant stress are introduced. Epidemiologic and experimental studies of the relationship between iron and breast cancer are reviewed. Extant studies involving phase II detoxication gene interactions with red meat consumption and breast cancer or iron-related gene polymorphisms and breast cancer are also reviewed. In conclusion, a model by which red meat may impact breast cancer involving the delivery of dietary iron is proposed and discussed.