Background: Gastric cancer is the fourth most common cancer and second leading cause of cancer-related death worldwide. A clear association between Helicobacter pylori infection and gastric cancer was established years ago. H. pylori eradication may be an effective approach to decrease morbidity and mortality of gastric cancer. Aim: To discuss current evidence of H. pylori eradication for prevention of gastric cancer. Results: Recent studies have shown that the association between H. pylori and gastric cancer has probably been underestimated. This may have resulted from negative H. pylori status in subjects after loss of colonisation in the presence of atrophic gastritis and intestinal metaplasia, prior to development of gastric cancer. The recognition of the central role of H. pylori in carcinogenesis has increased expectations of gastric cancer prevention by H. pylori eradication. A primary preventive effect of eradication in subjects with H. pylori-induced gastritis has been demonstrated. However, a secondary preventive effect in patients with pre-malignant gastric lesions is still controversial, especially in patients with intestinal metaplasia and dysplasia. Conclusions: At this moment, H. pylori eradication seems indicated at the earliest stage of gastric carcinogenesis. This treatment policy requires confirmation; results of ongoing randomised controlled trials are therefore eagerly awaited.