To investigate the effect of alcohol consumption on the risk of Helicobacter pylori infection, standardized questionnaires on drinking habits were used to interview 451 patients, whose H. pylori status was determined both by culture and serology. Reported alcohol consumption did not increase the risk of H. pylori infection (a 1.0 odds ratio, CI95 0.6-1.6). However, when the patients were divided into two age-groups, those under 35 years who reported to use alcohol seemed to have a slightly higher risk of H. pylori infection (a 3.3 odds ratio CI95 0.9-12.2) compared to those over 35 years (a 1.0 odds ratio, CI95 0.5-2.2). This phenomenon did not reach statistical significance. The type of alcohol consumed did not affect the age-adjusted risk of H. pylori infection. If pathologically defined chronic gastritis was found, the risk for H. pylori was high (a 26.7 odds ratio, CI95 12.1-59.0, for those under 35 years, and a 12.8 odds ratio, CI95 6.7-24.3, for those over 35 years of age.