This paper reviews the major studies on the possible relationship between drinking alcohol and breast cancer. The majority of these studies show some association between levels of alcohol consumption and breast cancer. However, the evidence of a causal link is lacking. A number of problems in interpreting the data are discussed. Given the high incidence of breast cancer in many countries, this is an important area. However, the imputed role of alcohol must not be exaggerated, particularly if this means that other more important factors in the equation fail to be examined.