The relationship between breast cancer and alcoholic beverage consumption was investigated in a case-control study of 437 women with breast cancer and 437 age-matched controls admitted to the hospital for acute conditions apparently unrelated to alcohol consumption. Compared to the relative risks (RR) for women who had never drunk alcohol, the RR for those reporting 1-3 and more than 3 alcoholic drinks per day were 1.24 and 1.93, respectively. A similar positive trend in risk with increasing daily consumption was evident for wine alone, and the point estimates were above unity for beer and spirits. Allowance for all identified potential confounding factors (including the major risk factors for breast cancer and a few selected dietary items) did not appreciably change any of the alcohol-related estimates. The RR, however, were higher at younger ages and did not rise with increasing duration of use. Nonetheless, the findings of the present study and their similarity with those of another case-control study conducted in northeastern Italy indicate that the association between alcoholic beverage consumption and breast cancer in this population is probably real, though not necessarily causal.