Helicobacter pylori infection has been identified as a pathogenic factor in a number of gastroduodenal diseases, most importantly in gastric and duodenal ulcer disease. This association and the development of H. pylori eradication therapies has had a tremendous influence on the surgical therapy for these disorders. Decades ago, surgery was the therapy of choice for gastric and duodenal ulcers. Now, however, the first line of therapy includes treatment of H. pylori infection, suppression of gastric acid secretion, and protection of gastric mucosal barriers combined with a range of endoscopic procedures. These developments have had a major impact on the indications for surgery in benign gastroduodenal diseases. In addition, advances in our understanding of the pathogenetic mechanisms of H. pylori infection have also changed our views of gastric mucosa-associated lymphoid tissue lymphoma, gastric cancer, and gastroesophageal reflux disease.