Background: Helicobacter pylori has been extensively studied since 1982 it is estimated that 50% of the world population is affected. The literature lacks studies that show the change of its prevalence in the same population over time. Aim: To compare the prevalence of H. pylori in 10 years interval in a population that was submitted to upper endoscopy in the same endoscopy service. Method: Observational, retrospective and cross-sectional study comparing the prevalence of H. pylori in two samples with 10 years apart (2004 and 2014) who underwent endoscopy with biopsy and urease. Patients were studied in three consecutive months of 2004, compared to three consecutive months of 2014. The total number of patients was 2536, and 1406 in 2004 and 1130 in 2014. Results: There were positive for H. pylori in 17 % of the sample as a whole. There was a significant decrease in the prevalence from 19.3% in 2004 to 14.1% in 2014 (p<0.005). Conclusion: There was a 5.2% reduction in the prevalence of H. pylori comparing two periods of three consecutive months with 10 years apart in two equivalent population samples.