Aim To evaluate frequency of administration of anticoagulant therapy (ACT) for atrial fibrillation and to study the effect of chronic antithrombotic therapy (ATT) on kidney function.Material and methods Due to a high medical and social significance of AF, much attention is presently paid to appropriate administration of ACT for AF in clinical practice. The study retrospectively analyzed 776 case reports of hospitalized patients with AF. The effect of chronic ATT on kidney function was studied in 70 patients who were rehospitalized, including 25 patients treated with warfarin, 25 patients treated with direct oral anticoagulants (DOAC), and 20 patients treated with acetylsalicylic acid (ASA).Results In January 2014, at the prehospital stage, 74.3 % of patients did not receive ATT, 14.7 % of patients received antiplatelet therapy, and only 11 % received anticoagulants. In the hospital in January 2014, ACTs were administered to 74.3 % of patients (warfarin, 58.6 %; DOAC, 15.7 %), 20.6 % of patients received antiplatelet drugs, and 5.1 % of patients were discharged without ATT. In January 2019, the number of patients receiving ACT at the prehospital stage increased to 58.1 % (warfarin, 13.8 %; DOAC, 44.3 %); 12 % of patients received antiplatelet drugs; and 29.9 % of patients did not receive ATT. The number of patients treated with warfarin and DOAC in the hospital increased to 14.8 % and 70.6 % (rivaroxaban, 33.4 %; apixaban, 25.5 %, and dabigatran, 11.7 %), respectively. The number of patients taking antiplatelet drugs decreased to 3.7 %, and the number of patients without ATT decreased to 10.9 %. There were no statistically significant differences in glomerular filtration rate (GFR) between these three groups at baseline. Only in the warfarin treatment group, GFR was significantly decreased from baseline during the follow-up period. Comparison of GFR in three study groups at the finale stage of the study showed significant differences between mean GFRs in the warfarin treatment group and the DOAC treatment group and between the warfarin treatment group and the ASA treatment group.Conclusion Among the prescribed and taken anticoagulants, DOACs are presently in the first place. Among DOACs, the most frequently prescribed drug is rivaroxaban. GFR decreases with the DOAC treatment slower than with the warfarin treatment. Despite the slower decrease in GFR with the ASA treatment compared to warfarin, ASA is not indicated for prevention of stroke in AF due to its low efficacy.