The prevalence of Helicobacter pylori-associated peptic ulcers, in particular duodenal ulcers, is decreasing following decreasing prevalence of H. pylori infection, while the frequency of non-steroidal anti-inflammatory drugs (NSAIDs)-induced and H. pylori-negative idiopathic ulcers is increasing. The incidence of bleeding ulcers has been stable during the last decades. Several putative H. pylori virulence genes, i.e., cag, vacA, babA, or dupA, as well as host-related genetic factors like IL-1beta and TNFalpha-gene polymorphism, have been proposed as risk factors for duodenal ulcer. H. pylori eradication may prevent NSAID complications, in particular, when it is performed before introduction of NSAIDs. There is a complex association between H. pylori and gastroesophageal reflux disease (GERD), and the impact of H. pylori eradication on the appearance of GERD symptoms depends on various host- and bacteria-related factors. Eradication of H. pylori in GERD is recommended in patients before instauration of a long-term PPI treatment to prevent the development of gastric atrophy. A small proportion (10%) of non-ulcer dyspepsia cases may be attributed to H. pylori and may benefit from eradication treatment. A test-and-treat strategy is more cost-effective than prompt endoscopy in the initial management of dyspepsia.