Objectives: Despite improved treatment during last 20 years, prognosis for patients hospitalized for acutely decompensated heart failure (ADHF) is poor and mortality rates reported for these patients are high. Laboratory results can assist clinicians in evaluation and triaging of patients on hospital admission, and are important for the medical decision-making and prognosis assessments. Recently, new guidelines for the diagnosis and treatment of acute and chronic HF patients were published introducing a new group of patients with mid-range left ventricular ejection fraction (LVEF). Methods: In order to explore the prognostic value for the in-hospital mortality of ADHF patients we analyzed laboratory test results for 165 emergency hospitalized patients regarding the survival and LVEF. Results: In-hospital mortality was 16%. Patients who died were older than survivals (p=0.003). There were no differences in LVEF between survivals and non-survivals. Patients who survived had significantly lower N-terminal pro-B-type natriuretic peptide (NT- proBNP), high-sensitivity cardiac troponin T (hs-cTnT), uric acid, urea, creatinine, and red blood cell distribution width (RDW) than patients who died (p<0.001). All these tests had a good discrimination power between survivals and non-survivals (p<0.001), but their incremental addition to NT-proBNP didn’t improve its overall prognostic value. There was only a very weak correlation between NT-proBNP concentrations and LVEF. Groups with different LVEF status showed significant difference in number of erythrocytes, RDW and hemoglobin concentrations. Conclusions: NT-proBNP had the best discriminatory power between survivals and nonsurvivals. Some routine laboratory test results, like RDW, uric acid, urea, and creatinine, have potentially significant value.