In a French case-control study of 1,010 breast cancer cases and 1,950 controls with nonmalignant diseases, the risk of breast cancer was found to be positively associated with frequency of cheese consumption and the level of fat in the milk consumed. A negative association was found between frequency of yogurt consumption and the risk of breast cancer. No association was found between the consumption of butter and the risk of breast cancer. The positive association between a daily consumption of alcohol and the risk of breast cancer previously reported was not altered when dairy produce consumption was taken into account.