The population attributable risk for oesophageal cancer in relation to cigarette smoking, elevated alcohol use and low beta-carotene intake has been estimated with 300 cases and 1203 controls in Greater Milan. In males 71% of oesophageal cancers were attributable to smoking, 45% to elevated alcohol use and 40% to low beta-carotene consumption. The corresponding figures were 32%, 10% and 29% in females and 61%, 39% and 38% in total. The overall estimate, including the joint effect of the three factors, was 90% in males, 58% in females and 83% in total. The discrepancies between the sums are due to the assumption of a multiplicative model and to the great percentage of oesophageal cancers attributable to each single factor. Cigarette smoking is the major known cause of oesophageal cancer and the three factors account for practically all the difference between male and female mortality rates. Elimination of smoking, reduction of alcohol consumption and enrichment of diet with fruit and vegetables would make oesophageal cancer a rare disease in Italians of both sexes.