The relationship between Helicobacter pylori (Hp) gastritis and gastroesophageal reflux disease (GERD) remains controversial. The aim was to investigate the association between Hp infection and gastroesophageal reflux (GER) and the impact of Hp eradication on esophageal acid exposure and motility in adolescents and young adults with Hp gastritis and GERD. Sixty-four patients with symptoms suggestive for GERD, of which 40 Hp-positive (group A) and 24 Hp-negative (group B), underwent endoscopy-biopsy, esophageal manometry and 24-hour pH-metry. All group A patients received eradication treatment and were re-evaluated six months later again with 24-hour pH-metry, esophageal manometry, endoscopy-biopsy and clinical assessment. At inclusion, there were no significant differences between the two groups regarding sex, age, grade of endoscopic esophagitis, manometric and pH-metry findings. All Hp-positive patients had an antral predominant gastritis. Eradication of Hp was successful in all patients, and gastritis and esophagitis were healed in all patients. The mean lower esophageal sphincter pressure (LESP) increased significantly from 11.25 mmHg before to 11.71 mmHg after eradication (P<0.05). A significant decrease in reflux index was observed (mean RI 6.02% before versus 4.96% after eradication (P<0.05). However clinical symptoms of GER improved not significantly after 6 months follow up. Conclusively, in children and young adults with GER symptoms and GERD, the presence or absence of Hp has no impact on manometric and pH-metric findings. Eradication of Hp infection results in increase in LESP with a consequent decrease in esophageal acid exposure but not significant clinical improvement.