AIM: To examine the relationship between H pylori and gastro-oesophageal reflux disease (GORD) in Iran. METHODS: In this study 51 GORD patients (referred to endoscopy at Taleghani hospital) were compared with 49 age-sex matched controls. Diagnosis of H pylori was made by gastric mucosal biopsy and rapid urease test (positive if the result of one or both diagnostic methods was positive). Updated Sydney system was used to report histopathological changes. RESULTS: The frequency of H pylori infection based on rapid urease test and histology was 88.2% (45) in patients and 77.6% (38) in controls, which showed no significant difference. The frequency of H pylori infection was significantly higher in the antrum than in the corpus and cardia. The mean activity, inflammation, and gastritis scores were also higher in the antrum of patients than in the antrum of controls. The mean scores were significantly higher in the corpus of controls than in the corpus of patients. Diffuse active gastritis was observed in a significantly larger number of controls, while the frequency of diffuse chronic gastritis was higher in patients. There was no significant difference in the frequency of other histological findings between patients and controls.CONCLUSION: H pylori infection cannot prevent GORD in this region. AIM: To examine the relationship between H pylori and gastro-oesophageal reflux disease (GORD) in Iran. METHODS: In this study 51 GORD patients (referred to endoscopy at Taleghani hospital) were compared with 49 age-sex matched controls. pylori was made by gastric mucosal biopsy and rapid urease test (positive if the result of one or both diagnostic methods was positive). Updated Sydney system was used to report histopathological changes. RESULTS: The frequency of H pylori infection based on rapid urease test and histology was 88.2% (45) in patients and 77.6% (38) in controls, which showed no significant difference. The frequency of H pylori infection was significantly higher in the antrum than in the corpus and cardia. The mean activity, inflammation, and the mean scores were significantly higher in the corpus of controls than in the corpus of patients. Diffuse active gastritis w there was no significant difference in the frequency of other histological findings between patients and controls. CONCLUSION: H pylori infection can not prevent GORD in this region .