Within the framework of the German National Health interview and Examination Survey determinations of IgG-antibodies against the bacterium Helicobacter pylori in serum samples of study participants were conducted. The prevalence for the total population of Germany was 40%. No differences could be found between sexes. The comparison between study participants from the old and those from the new (territory of the former GDR) federal states of Germany did show that the prevalence rates were significantly higher in all age-groups of the eastern part (former GDR) of Germany. Possible causes and factors of influence are discussed.