bstract Background: Infection with the bacteria Helicobacter pylori is frequent in both young and old. Antibiotic susceptibility testing on an individual or community level, as well as data on antibiotic use and clinical outcomes, should inform the most effective local regimen for eradication. Objective: The aim of the current work was to evaluate the efficacy of commonly used antibiotics against Helicobacter pylori and to determine diagnostic stool antigen test accuracy performed after H. pylori medical treatment. Patients and Methods: This prospective single arm cohort study included a total of 55 patients who tested positive for H. pylori, followed at Departments of Tropical Medicine and Pathology, Zagazig University Hospitals. This study was conducted between July 2020 and January 2021. Results: H. pylori infection was more common in middle age group 32.6±8.58 and more in female (56.4%). The most frequent presentations were dyspepsia (63.6%), epigastric pain (23.6%) and abdominal fullness 12.7% of the cases. Gastritis 49.1%, duodenitis 32.7%, gastric ulcer 12.7% and duodenal ulcer 10.9%, are the common endoscopic diagnosis in H. pylori infection. After therapy, there was a moderate statistically significant agreement between biopsy and stool in diagnosis of H. pylori infection with sensitivity 90%, but specificity 73.3% and accuracy 76.4%. Conclusion: It could be concluded that Helicobacter Pylori stool antigen test is highly sensitive with moderate specificity and accuracy for diagnosis of H. pylori infection post anti H. pylori therapy.