Objective. To evaluate the burden of atrial fibrillation (AF).Material and methods. Direct and indirect costs were cal-culated on the basis of epidemiological and clinical data on AFin North-West Federal Region.Results. Calculated prevalence of AF is 3,2 per 1000. Thetotal number of AF cases in Russia is around 2,5 mln. Thenumber of hospitalizations may reach 1.227 mln annually, themean number of patient days for one case of AF is 6,9 days,mortality is 1%, total number of temporary disability daysmay reach 3,386 mln. Greater part of the expected costs is thehospitalization cost (59%), total cost per 1 patient is 41 thou-sand RURs.Conclusion. AF is a socially significant and costly condi-tion. The social and personal losses may be decreased byimprovement of out-patient care and pharmacotherapy.