Abstract Background and Aims to study the features of the functional state of the kidneys in patients with chronic heart failure with intermediate ejection fraction, depending on the representation of components of metabolic syndrome Method To achieve the objectives, 197 male patients with chronic heart failure (CHF) of ischemic origin II - III functional class (FC) according to NYHA, aged 40-60 years with a history of myocardial infarction of 6 months, were examined. up to 5 years. Depending on the presence of MS components, 3 groups of patients were identified: group I (n = 70), patients without MS (CHF FC II -38, CHF FC III - 32 patients); Group II (n = 67) patients with various combinations of dyslipidemia (HDL-C <1.03 mmol/l; LDL-C >3.0 mmol/l) with AO, hypertension and HTG (CHF FC II -35, CHF FC III - 32 patients); Group III (n = 60) patients with various combinations of dyslipoproteinemia (DLP) and type 2 diabetes mellitus (DM2) with AO, hypertension and HTG (CHF FC II -26, CHF FC III - 34 patients). When diagnosing MS, the International Diabetes Federation diagnostic criteria for MS were used (IDF, 2009). The study of the functional state of the kidneys included determination of the level of serum creatinine, urinary albumin excretion (determination of microalbuminuria (MAU ≥300 mg/l), glomerular filtration rate (GFR), calculated using the GFR EPI formula. Results when studying the parameters of the functional state of the kidneys in patients with CHF HFmrEF group 1, MAU was identified in 10 patients (35.7%) out of 28. Serum creatinine clearance in this group was 89.0 ± 8.49 μmol /l, and the GFR level was 88.58 ± 8.36 ml/min. With the development of MS in group II patients, 16 out of 28 patients had MAU (53.6%). A decrease in GFR was also found by 11.3% ( P < 0.05) with an increase in serum creatinine levels by 12.7% (P < 0.01), in contrast to the data from group I of the study. Further analysis of the parameters of renal function in group III of CHF HFmrEF revealed a significant decrease in GFR (by 23.0%; P < 0.01) with a significant increase in blood creatinine levels (by 21.8%; P < 0.01) in relation to the data Group I. Also in group III of patients with CHF and MS (+DM2 ), microalbuminuria was detected in 24 patients (85.7%) out of 32 . When comparing indicators of renal function between study groups II and III, there was a significant difference in the level of blood creatinine clearance and glomerular filtration rate by 11.3% and 10.1% (P < 0.05), respectively. Conclusion MS in patients with CHF HFmrEF aggravates renal dysfunction, which developed as one of the main pathogenetic links of CHF. Evidence of the importance of MS in the nature of the clinical manifestations of CHF HFmrEF is the established dependence of the identified disorders on the severity of MS.