The present study evaluated the time in remission during a 2-year follow-up after eradication of Helicobacter pylori (HP) in patients with an HP-associated duodenal ulcer (DU). HP was eradicated by combined treatment with high-dose omeprazole (2 x 40 mg) and amoxicillin (2 x 1,000 mg; n = 27) administered for 10 days (OME + AMX); alternatively, patients were treated with omeprazole monotherapy (OME) using the same dosage (n = 25). During the 2-year follow-up period endoscopy including histological examination was performed after 1 and 2 years or whenever symptoms compatible with ulcer relapse occurred. HP eradication was achieved in 82% of the OME + AMX group, but in 0% of the OME group. The cumulative DU relapse rates were 0% after 1 year and 7% after 2 years in 22 patients who became HP-negative. Both HP-negative patients who relapsed in the 2nd year of follow-up were HP-positive again at the time of relapse. Of the 5 patients who were not eradicated after OME + AMX therapy, 2 relapsed within the 1st year (40%) and another 2 within the 2nd year (80%). In the OME group the cumulative relapse rates within 1 and 2 years of follow-up were 52 and 76%, respectively. The results further confirm that eradication of HP with combined OME + AMX treatment leads to a distinct decrease in DU relapse rates and thus may cure DU disease. Long-term eradication with combined OME + AMX treatment is possible, and the rate of reinfection with HP is low (4.5%/year).