Eradication of Helicobacter pylori (Hp) infection is strongly recommended in duodenal and gastric ulcer. In developed countries the recurrence rate is low; however, in Turkey, the Hp recurrence rate is suspected to be high as the prevalence of Hp infection is-as high as 70-80% in the asymptomatic population. We planned this study to determine the relapse rate of Hp infection after successful eradication therapy in Turkey. Fifty-two cases including 24 patients with duodenal ulcer and 28 patients with nonulcer dyspepsia were examined in this study. The eradication regimen was omeprazole 20 mg twice daily, clarithromycin 500 mg twice daily, and metronidazole 500 mg three times a day for 1 week. All patients underwent upper gastrointestinal tract endoscopy. At least four samples from antrum and corpus were taken to enable histologic diagnosis of Hp infection. After the eradication therapy, endoscopy was repeated at 1, 3, 6, and 12 months, and Hp-positive patients were dropped from study. With the use of this regimen, the Hp eradication rate was 92.3% (48/52). After the eradication of Hp infection, relapse rates were 6.97%, 27.5%, and 11.11% at 3, 6, and 12 months, respectively. The cumulative relapse rate for 1 year was 41.46%. The results of this study revealed that after the eradication of Hp infection, recurrence is encountered very often as a problem in Turkey. We concluded that hygienic and environmental factors can affect these high relapse rates.