It is now recognised that Helicobacter pylori, like most enteric infections, is mainly acquired in childhood. Adults rarely become infected, with seroconversion rates varying between 0.33and 0.5% per person year. The age at which children are most likely to become infected is still unclear, but findings in a number of cross-sectional studies suggest that infection is acquired before the age of five. The prevalence of infection is highest in children in the developing world where up to 75% of children may be infected by the age of 10. In the developed world the prevalence of infection is noticeably increased among socially deprived children. The diagnosis of H pylori infection in childhood is most often made at endoscopy, for which there are many indications. Symptoms such as abdominal pain, vomiting, and haematemesis may be associated with duodenal ulcer and H pylori infection. However, in the case of children undergoing endoscopy for assessment of oesophagitis, failure to thrive, coeliac disease, Crohn's disease, or portal hypertension, the finding of H pylori infection is likely to be incidental. How should we manage these children with a diagnosis of H pylori infection? Currently, there are no consensus guidelines for the management of H pylori infected children. In 1994 the National Institutes of Health consensus statement recommended that adults with gastric or duodenal ulcer disease, who are infected with H pylori, should receive antimicrobial treatment. The European Maastricht Consensus Report suggested broader indications for treatment of infected adults. It states that treatment is advisable for all H pylori infected dyspeptic patients diagnosed non-invasively under 45 years of age at a primary care level. Patients older than 45 years with dyspeptic symptoms should be treated for H pylori infection but only after endoscopy to rule out any other underlying pathology. The European guidelines also recommend treatment for infected patients with mucosa associated lymphoid tissue lymphoma and patients who are found to have intestinal metaplasia and gastric atrophy.