The drinking habits of 86 men with adenomatous polyps of the sigmoid colon were compared to those of 1184 men with normal colonoscopy among middle-aged male self-defence officials. After adjustment for rank, smoking history and rice consumption, total ethanol intake was positively associated with the risk of adenomatous polyps. The odds ratio (OR) was 2.4 (95% confidence interval (CI) 1.0-5.5) for men consuming at least 60 ml of ethanol per day. Among five alcoholic beverages (shochu, beer, sake, whiskey and wine), both sake and beer showed a dose-response relationship with the risk of adenomatous polyps although the association with beer was less striking. Shochu was the largest source of ethanol intake in the study population, but there was virtually no association between shochu consumption and adenomatous polyps. Men drinking wine had a significantly increased risk, but these men were too few to examine the relation in detail. The findings suggest that the consumption of specific alcoholic beverages rather than ethanol itself is associated with an increased risk of adenomatous polyps of the sigmoid colon.