Epidemiology is a scientific discipline concerned with the distribution and determinants of health and diseases, morbidity, injuries, disability and mortality in populations. This article reviews the literature on women's breast cancer from an epidemiological point of view. Special attention is given to epidemiology and cancer in terms of sources of information, geographical variations, incidence and mortality, risk factors and prevention. Iceland and Scotland were chosen to compare and contrast the epidemiology of breast cancer. These countries were chosen because of the author's general knowledge and acquaintance with both countries and because of her experience in working with breast cancer patients.