Helicobacter pylori infection is frequent in children. Its incidence in Europe, around 6% in children aged 6-16 years, varies with the socio-economic level and nutritional status. It may reach 46% in Africa and up to 75% in some institutions. Clinical manifestations debated. Vomiting, dyspepsia and acute pain related to ulcer disease may undisputedly be linked to H. pylori, whereas its role in chronic abdominal has yielded contradictory reports. Direct isolation of the bacterium is classically done through perendoscopic antral biopsies followed by culture and histology. Non-invasive diagnosis methods get a wider use in children. Serodiagnosis is reproducible and easy only in older children. The 13C-urea breath test is sensitive and specific, and seems perfectly suitable in pediatrics. The H. pylori stool antigen test for the detection of infection seems promising but not yet of current clinical use. Triple therapy using amoxicillin-clarithromycin (or metronidazole or tinidazole) and anti-secretory agents is recognised as the most efficient association.