The clinical recognition ofHelicobacter pylorigastritis in children with recurrent abdominal pain is difficult. We assessed the value of a simplified13C urea breath test (13C-UBT) in a selected group of children with nocturnal waking and disruptive recurrent abdominal pain who fulfilled criteria for endoscopy. Gastric antral biopsies were examined histologically and by the quick urease test and were compared withH. pyloriserology and the13C-UBT in a prospective study of 50 children referred to a tertiary center. Thirty-two patients had gastritis and of these, 19 had histologically provenH. pylorigastritis. Seventeen of these 19 patients had a positive13C-UBT. The sensitivity and specificity of the13C-UBT compared with the histologic diagnosis ofH. pyloriwas 89 and 90% respectively. The13C-UBT was more specific than theH. pyloriserology. The13C-UBT using two breath collections is a reliable and noninvasive diagnostic test forH. pyloriinfection in children.