Our aim was to evaluate diagnostic accuracy of rapid immunochromatographic stool antigen test (Rapid HpSA; LINEAR Chemical, Barcelona, Spain) and a practical low-dose (14)C urea breath test (UBT) (Heliprobetrade mark) test before and after eradication therapy. One hundred nine children with abdominal symptoms (age range, 5-17 years; mean, 12.1) underwent endoscopy, (14)C-UBT, and Rapid HpSA. Patients were defined as Hp infected when histology was positive for Hp. Forty children (36.6%) were Hp infected. The sensitivity of Rapid HpSA and (14)C-UBT was 65% and 92.5% (P = 0.0003), respectively; the specificity of Rapid HpSA and (14)C-UBT was 92.3% and 85.5% (P = 0.180), respectively. After eradication therapy endoscopy, (14)C-UBT and Rapid HpSA were repeated. The eradication rate was 70.5%. After eradication, the sensitivity of Rapid HpSA and (14)C-UBT was 60% and 100%, respectively; the specificity of Rapid HpSA and (14)C-UBT was 100%. (14)C-UBT was more reliable than the Rapid HpSA test for the diagnosis and for confirming eradication of Hp infection.