Patients with intractable peptic ulcer or recurrent peptic ulcer have high rate of Helicobacter pylori infection. To study the effect of H. pylori on the recurrence of peptic ulcer, we treated the patients, who had H. pylori infection, with antibiotics (amoxicillin, clarithromycin, fosfomycin). After one year, none of peptic ulcer patient in whom H. pylori was eradicated had a recurrence. Among patients who remained positive for H. pylori, the ulcer relapse rate was 61% (11 of 18). In patients who were successfully eradicated of H. pylori with antibiotics the rate of recurrence was reduced. Patients with both intractable peptic ulcer and H. pylori infection were treated with antibiotics. Eradication of H. pylori induced ulcer healing. These findings suggest an important role for H. pylori in intractable and recurrent peptic ulcer.