Background: The effect of Helicobacter pylori (H. pylori) eradication on gastr oesophageal reflux disease is controversial. We aimed to investigate the effect of H. pylori eradication in this group of patients. Materials and Methods: Thirt y-four consecutive patients with H. pylori infection and reflux esophagitis (gr ade 1 or 2) were enrolled into the study. Twenty-four hour intra-esophageal pH recording and esophageal manometry were performed before and 3 months after era dication of H. pylori, which was achieved using lansoprazole 30 mg b.i.d., amoxy cillin 1 g b.i.d., and clarithromycin 500 mg b.i.d. for 14 days. H. pylori was e valuated in biopsy specimens taken from the antrum and corpus by rapid urease te st and by histopathologic examination before and 3 months after eradication. Res ults: Eighteen patients (11 men and 7 women, median age 42 years) completed the study. Three months after the treatment, there was no significant change in any of the 24-hour esophageal pH recording parameters and mean lower esophageal sph incter resting pressure (P > 0.05). The percentage of total time esophageal pH< 4 increased in 10 patients, and decreased in 8 patients. There was a significant decrease in the scores of heartburn and regurgitation (P < 0.01). Esophagitis p ersisted in 16 patients and disappeared in 2 patients. Esophagitis score decreas ed in 6 patients, and did not change in 12 patients (P < 0.05). Conclusion: H. p ylori eradication does not have any effect on gastroesophageal acid reflux in pa tients with reflux esophagitis 3 months after eradication, but significant impro vement is achieved in some reflux associated symptoms. Background: The effect of Helicobacter pylori (H. pylori) eradication on gastr oesophageal reflux disease is controversial. We aimed to investigate the effect of H. pylori eradication in this group of patients. Materials and Methods: Thirt y-four consecutive patients with H . Pylori infection and reflux esophagitis (gr ade 1 or 2) were enrolled into the study. Twenty-four hour intra-esophageal pH recording and esophageal manometry were performed before and 3 months after era dication of H. pylori, which was achieved using lansoprazole 30 mg bid, amoxycillin 1 g bid, and clarithromycin 500 mg bid for 14 days. H. pylori was evaluated in biopsy specimens taken from the antrum and corpus by rapid urease st and by histopathologic examination before and 3 months after eradication. Three months after the treatment, there was no significant change in any of the 24-hour esophageal pH recordin (11 men and 7 women, median age 42 years) The percentage of total time esophageal pH <4 increased in 10 patients, and decreased in 8 patients. There was a significant decrease in the scores of heartburn and regurgitation (P <0.01). Esophagitis score decreas ed in 6 patients, and did not change in 12 patients (P <0.05). Conclusion: H. p ylori eradication does not have any effect on gastroesophageal acid reflux in pa tients with reflux esophagitis 3 months after eradication, but significantly impro vement is achieved in some refluxes associated symptoms.