To determine the 10 most significant advances in gastroenterology during this century as we approach the millennium, the authors polled 50 distinguished active clinicians and leading researchers in the field, including workers in liver disease and the pathology of the gut and its associated glands. Forty-five persons (90%) responded and listed 58 different items. These were then organized into four groups: group A, with 10 categories that received between 42 and 11 votes; group B, with 10 categories that received between 10 and 3 votes; group C, with 3 items receiving 2 votes each; and group D, with the remaining 14 items receiving 1 vote each. The respondents did not indicate their choices in rank order. The top 10 leading choices (group A, containing between 42 and 11 votes) includedHelicobacter pylori,fiberoptic endoscopy, gastrointestinal imaging by radiograph and computed tomographic scan, Australia antigen including vaccines for hepatitis A and B, the molecular basis of colon cancer, liver transplantation, laparoscopic-assisted surgery, therapy for peptic ulcer disease including H2-receptor antagonists and proton pump inhibitors, the discovery of gastrointestinal hormones beginning with secretin, and lastly the discovery of the role for gluten in celiac disease.