Heart failure (HF) and renal dysfunction are frequent associated in the same patient. The purpose of our study was to assess the prevalence of renal dysfunction and the clinical status in admitted patients for decompensated HF. Material and Methods. 397 patients succesively hospitalized for decompensated HF, NYHA III or IV functional class, with left ventricular ejection fraction (LVEF) � 45% were included in the study. Renal dysfunction was defined by glomerular filtration rate (GFR) [ 60 mL/min/1.73 m 2. The mean GFR in patients with HF was 63.89 � 21.5 mL/min/1.73 m2 .The prevalence of renal dysfunction was 49.6%. Patients with GFR [ 60 mL/min/1.73m2, compared with those with preserved renal function were significantly more frequent older (75.37 � 6.84 vs. 71.33 � 8.08 years; p [0.001), females (53,8% vs. 43.5%; p = 0.04), had a significantly higher prevalence of diabetes mellitus (50.2% vs. 28.5%; p [0.001), atrial fibrillation (53.8% vs 46.2%, p = 0.04) and anemia (47.7% vs. 29.5% ; p [0.001). Also, patients with renal dysfunction had more severe HF than those without renal dysfunction (NYHA class IV: 65% vs 45%, p [0.001, clinical congestion: 78.2% vs 68%, p = 0.02, LVEF [35%: 47.21% vs � 35%, p [0.001). Renal dysfunction can be considered an additional marker of severe cardiac dysfunction along with NYHA IV class and low LVEF. The presence of both renal dysfunction and anemia could represent prognostic markers in HF patients with reduced LVEF.