There is evidence that Helicobacter pylori infection is associated with gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma and possibly with non-ulcer dyspepsia. Eradication therapy for confirmed H. pylori infection may therefore become mandatory in patients with non-ulcer dyspepsia severe enough to warrant endoscopy and in first-degree relatives of patients with gastric cancer. However, routine treatment of asymptomatic carriers awaits confirmation of the association with cancer.