This study presents the first account of the prevalence of headache syndromes, defined according to the International Headache Society criteria, in a large representative sample of the German population; 5000 persons representative of the total population were selected from 30,000 households. Subjects were requested to answer a questionnaire about headache occurrence during their lifetime. The completion rate was 81.2%. Seventy-one point four percent (n = 2902) reported a history of headache. Twenty-seven point five percent fulfilled the criteria for migraine. Thirty-eight point three percent (n = 1557) met the criteria for tension-type headache and 5.6% (n = 229) did not fulfil criteria for either migraine or tension-type headache. Significant correlations were found between the prevalence of the different headache syndromes and sociodemographic variables such as sex, age and place of residence. The prevalence of headache did not exhibit any significant differences between the various länder (states or regions) of Germany. When extrapolated to the total population these results reveal that 54 million people in Germany suffer from headache at least occasionally or persistently. These findings suggest that the magnitude of the neurological disorders, migraine and tension-type headache, is seriously underestimated and thus constitutes a major contemporary health problem.