The role of alcohol consumption (alcoholic calories, alcoholic beverages) on breast cancer risk was investigated in a case-control study of 154 premenopausal female patients diagnosed with primary breast carcinoma. For each case, one control was matched for age (+/- 3 years) and socio-economic status. The survey was carried out in Northeastern France (Lorraine) between 1986 and 1989. While taking into account total caloric intakes and various breast cancer factors, breast cancer risk was shown to increase as consumption of alcohol increased (p value for trend = 0.007). A significant relative risk (RR = 2.69; 95% CI: 1.40-5.17) was shown above 60 kcal per day (approximately 9 g of alcohol per day). Breast cancer risk appeared to be restricted to red wine consumption among these premenopausal women, for monthly consumption (p value for trend = 0.003) as well as for duration of consumption (p value for trend = 0.01). A relative risk of 3.96 (95% CI: 1.59-9.84) was found for a monthly consumption higher than 4 liters per month. This reinforces the notion of a particular sensitivity of young women to breast cancer in relation to alcohol consumption.