The prevalence of Helicobacter pylori is influenced in a significant way by geographical conditions and depends to a certain extent also on the economic standard of different countries. Some published work provides evidence that Helicobacter pylori infections in eastern European countries are in general more frequent than in western European countries. It cannot be ruled out, however, that in different countries there are regional differences as far as Helicobacter pylori is concerned. In a group of 309 subjects, none of those treated previously to eradicate H.pylori, at least three weeks before blood sampling no preparations of the type of H2 blockers, proton pump blockers or drugs containing bismuth were administered. In these patients serological examinations of H.pylori antibodies were made, using kits of TEST-LINE Brno. The examined subjects were divided into six age groups by decades, starting at the age of 20 years. The general prevalence of H.pylori in the examined group was 58.8%, in the group of 20-year-old ones less than 46%. The highest prevalence was recorded in subjects aged 50-59 years and amounted to 67.3%. The authors compare their own results with findings assembled in the Czech Republic and abroad and draw attention to the necessity of an extensive epidemiological survey of H.pylori prevalence in the Czech Republic. The survey should be done by regions, using the same diagnostic method.