The clinical recognition of Helicobacter pylori gastritis in children with recurrent abdominal pain is difficult. We assessed the value of a simplified 13C 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 with H. pylori serology and the 13C-UBT in a prospective study of 50 children referred to a tertiary center. Thirty-two patients had gastritis and of these, 19 had histologically proven H. pylori gastritis. Seventeen of these 19 patients had a positive 13C-UBT. The sensitivity and specificity of the 13C-UBT compared with the histologic diagnosis of H. pylori was 89 and 90% respectively. The 13C-UBT was more specific than the H. pylori serology. The 13C-UBT using two breath collections is a reliable and noninvasive diagnostic test for H. pylori infection in children.