OBJECTIVES The aims of this contribution are to update and more precisely quantify the age and gender-specific prevalence and incidence of atrial fibrillation (AF) in an European setting (Germany). METHODS To fulfill the aims of the study, it was decided to make a population-based analysis of the claims data collected by a statutory health insurance fund, and concerning its 8.298 million members. A patient was classified as AF prevalent if he/she had received at least two outpatient diagnoses of AF (ICD10-Code I48.1) in two different quarters of the year and/or had received at least one main AF diagnosis during inpatient treatment between January 1, 2007 and December 31, 2008. A patient was considered to have had new onset AF in 2008 under one of three conditions; firstly, he/she had not received a diagnosis of AF in 2007; secondly, had not received oral anticoagulant medication in 2007; and thirdly, had received either one inpatient AF diagnosis in 2008, or two such outpatient diagnosis made in different quarters of that year. AF prevalence is reported in %, AF incidence is reported as cases per 1000 person-years. RESULTS In our sample, a total of 176,891 patients had AF. By reference to the total membership of the two medical insurance funds, the prevalence of AF was 2.132% (men: 2.369 %; women: 1.895%). The average age of these AF patients was 73.1 years, and 55.5% (98,190 patients) were male. The incidence of AF in our sample was 4358 cases per 1000 person-years in men and 3.868 cases in 1000 person-years in women. AF prevalence/incidence clearly depends on age and gender. CONCLUSIONS A comparison of the distribution of AF prevalence/incidence in our population with that in already published studies shows that our figures are higher, especially in the age groups above 70 years. Obviously, AF prevalence/incidence are further increasing in industrialized countries.