Existing evidence leaves little room for doubt that alcoholic beverages are carcinogenic. Alcohol is a risk factor for cancer of the oral cavity, larynx, esophagus, and possibly the liver. The extent to which carcinogenicity is attributable to the alcohol per se, or to other components of some or all of the beverages that contain it, is unclear. The alcohol effect, at least for cancers of the upper aerodigestive tract, depends on tobacco consumption. About 3% of all U.S. cancers in 1974 are attributable to alcohol; the small proportion and the dependence on tobacco mitigate against antidrinking campaigns for the primary prevention of cancer. It is likely that antismoking campaigns would be more effective than antidrinking campaigns in preventing alcohol-related cancers.