Alcohol has strong antimicrobial activity and stimulates gastric acid secretion. Alcohol consumption may therefore compromise the living conditions of Helicobacter pylori in the stomach. We assessed the relation of alcohol consumption with H. pylori infection among 1,785 participants ages 18-88 in the German National Health and Nutrition Survey. Detailed information on dietary and lifestyle habits was obtained in personal interviews using a standardized food frequency questionnaire. Serum samples were analyzed for H. pylori immunoglobulin G antibodies by enzyme-linked immunosorbent assay. Overall prevalence of H. pylori infection was 39.2%. There was a clear inverse dose-response-relation between reported alcohol consumption and H. pylori infection. The relation persisted after control for potential confounding factors. The adjusted prevalence ratios (95% confidence intervals) for H. pylori infection among persons who consumed up to 10, 10 to 20, and more than 20 gm of alcohol per day compared with non-drinkers were 0.93 (0.77-1.13), 0.82 (0.65-1.04), and 0.71 (0.55-0.92). The inverse relation between alcohol consumption and H. pylori infection was even stronger when individuals with an indication of a recent change of alcohol consumption were excluded from the analysis. These findings support the hypothesis that moderate alcohol consumption may facilitate spontaneous elimination of H. pylori infection among adults.