It has been recently reported that curing Helicobacter pylori (H. pylori) infection may provoke reflux esophagitis. We studied the effect of cure of H. pylori infection on the development of disorders of the upper gastrointestinal (UGI) tract. The estimated incidence of reflux esophagitis, gastric erosions and duodenal erosions after cure of infection was 8.9%, 32.8% and 8.9%. The incidences of reflux esophagitis, gastric erosions and duodenal erosions were 10.0%, 30.0% and 6.7% in patients with gastric ulcer, 2.8%, 36.1% and 27.8% in those with duodenal ulcer and 9.2%, 30.3% and 1.3% in those with atrophic gastritis. Therefore, patients whose H. pylori infection has been cured should carefully be investigated by endoscopy for H. pylori-associated disease.