Aim of work: to assess the reliability of H. pylori stool antigen test in detection of H. pylori infection in childhood. Comparing its sensitivity against the known golden standard diagnostic Urea breath test (UBT).Methodology: 60 pediatric patients were selected from Tropical Pediatric clinic of New Children Hospital, Cairo University. Their ages ranged from 2 to 15 years old. The main presentations were recurrent abdominal pain (76.7%), persistent vomiting (23.3%), growth failure (20%) and heamatemesis (5%). Children underwent: clinical assessment, UBT and stool antigen. Results: 35 children positive UBT and stool antigen, 22 children negative UBT and stool antigen and 3 children positive UBT and negative stool antigen. Sensitivity of stool antigen used in this study (lateral flow immunoassay)58.3%. There is an excellent agreement with UBT. Conclusion: stool antigen is good diagnostic method for H. pylori infection in children, in addition it is simple, cost-effective and easy way for screening and long term follow up of cases after therapy.