Objective: There are studies that conclude that Helicobacter pylon is transmitted through fecal oral and oral oral routes. In this study, we aimed to determine the source and mode of transmission of H. pylon in H. pylori infected patients by comparing H. pylori species isolated both from drinking water samples and gastric mucosa samples obtained by endoscopy from people who had dyspeptic symptoms and had been using these sampled water supplies as drinking water by biochemical and genotypic analysis.