Helicobacter pylori infection is usually acquired during childhood, and evidence-based guidelines regarding diagnosis and treatment of infected children have been recently published. Diseases associated with H. pylori infection are gastritis, duodenal ulcers, mucosal-associated lymphoid-type (MALT) lymphoma, and gastric adenocarcinoma. The association of specific symptoms with H. pylori infection in children and adults (ie, recurrent abdominal pain and nonulcer dyspepsia) remains controversial. Additionally, the role of H. pylori in gastroesophageal reflux disease or in extra-gastrointestinal diseases (ie, coronary artery disease) lacks sufficient evidence to demonstrate causality. The diagnosis of H. pylori-associated diseases in children can reliably be made through gastroduodenal endoscopy with biopsies. Clinical trials are underway for the validation of noninvasive diagnostic tests for the H. pylori-infected child, and current guidelines recommend eradication therapy for infected children with duodenal and gastric ulcer, gastric lymphoma, and atrophic gastritis with intestinal metaplasia. The natural history of childhood H. pylori infection is poorly described. Moreover, rational approaches to the prevention and control of childhood H. pylori infection are critically needed, requiring characterization of the determinants for acquisition and persistence and the disease outcomes following eradication.