Objectives: a) to determine the rate of H. pylori reinfection after successful eradication in a 4-year follow-up study; and b) to evaluate the contribution of different factors in the infection relapse.Patients and methods: a total of 208 patients (age range 18-81 years; average 50 years; 87 women) who had been successfully treated for H. pylori infection were included. Annually, urea breath test was assessed to determine H. pylori status after eradication. Age, sex, rural/urban environment, smoking habit, treatment regimens against H. pylori and urea breath test values were evaluated.Results: reinfection occurred in 9,6% of patients observed, 6,7% (14/208) in the first year, 1,9% (4/208) in the second year, 1% (2/208) in the third and 0% in the forth. Risk factors for infection recurrence were younger age and higher values of urea breath test in the multivariante analysis.Conclusions: annual reinfection rate was 2,4 pacients-year. Younger patients and higher values of urea breath test were factors associated with a higher rate of reinfection relapse. Annually, urea breath test should be performed to detect reinfection in order to avoid ulcer complications.