Aim To determine the effect of sodium-glucose cotransporter-2 inhibitors (SGLT2i) on kidney function in acute decompensated heart failure (ADHF).Material and methods A controlled randomized study on the dapagliflozin treatment in ADHF was performed. Patients were randomized to a main group (standard therapy supplemented with dapagliflozin) or a control group (standard therapy for ADHF). The primary endpoint was the development of acute kidney injury (AKI). 200 patients were included (mean age, 74±12 years; 51% men). 31% of patients had type 2 diabetes mellitus (DM2). Mean left ventricular ejection fraction (LV EF) was 47±14 %; in 44.5% of patients, LV EF was less than 45%. Median concentration of N-terminal pro-brain natriuretic peptide (NT-proBNP) was 5225 [3120; 9743] pg / ml, glomerular filtration rate (GFR) was 51 [38; 64] ml / min / 1.73 m2.Results In-hospital mortality was 6.5%. Analysis of the dynamics of body weight loss showed significant differences (4200 [2925; 6300] g vs. 3000 [1113; 4850] g; p=0.011) in favor of the dapagliflozin group. The requirement for increasing the daily dose of furosemide and adding an another class diuretic (thiazide or acetazolamide) did not differ between the groups. However, median furosemide dose during the stay in the hospital was lower in the dapagliflozin group (80 [67; 120] mg vs. 102 [43; 120] mg; p=0.016). At 48 hours after randomization, GFR significantly decreased in the dapagliflozin group (-5.5 [-11; 3] ml/min/ 1.73 m2) compared to the control group (-0.3 [-4; 5] ml / min/1.73 m2, р=0.012). Despite this, GFR did not differ between the groups at discharge (51 [41; 66] ml/min/1.73 m2 and 49 [38; 67] ml/min/1.73 m2, respectively; p = 0.84). In the dapagliflozin group, frequency of AKI episodes was not increased compared to the control group (13 and 9.4%, respectively; p = 0.45).Conclusion The dapagliflozin treatment in ADHF is associated with more pronounced body weight loss and lower average doses of loop diuretics during the period of stay in the hospital, with no associated clinically significant impairment of renal function.