Helicobacter pylori (H. p.) causes active chronic antrum gastritis in all infected patients. In a relatively small percentage complications of H. p.-gastritis including duodenal ulcer, gastric ulcer, giant fold gastritis, lymphocytic gastritis, autoimmune gastritis, gastric carcinoma and gastric MALT lymphoma may develop. Strongly recommended indications for eradication therapy include gastroduodenal ulcer disease, giant fold gastritis, lymphocytic gastritis, autoimmune gastritis, gastric MALT lymphoma, atrophic gastritis, corpus-predominant gastritis, post gastric cancer resection and patients who are first degree relatives of gastric cancer patients. Eradication therapy is controversial in patients with gastroesophageal reflux disease, functional dyspepsia and in patients in whom treatment with nonsteroidal antiinflammatory drugs (NSAID) or long-term treatment with proton pump inhibitors (PPI) is planned.