Alcohol has strong antimicrobial activity and stimulates gastric acid secretion. Alcohol consumption may therefore compromise the living conditions ofHelicobacter pyloriin the stomach. We assessed the relation of alcohol consumption withH. pyloriinfection 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 forH. pyloriimmunoglobulin G antibodies by enzyme-linked immunosorbent assay. Overall prevalence ofH. pyloriinfection was 39.2%. There was a clear inverse dose-response-relation between reported alcohol consumption andH. pyloriinfection. The relation persisted after control for potential confounding factors. The adjusted prevalence ratios (95% confidence intervals) forH. pyloriinfection 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 andH. pyloriinfection 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 ofH. pyloriinfection among adults. (Epidemiology 1999;10:214–218)