Compared with heart failure (HF) with reduced ejection fraction (HF-REF), the diagnosis of HF with preserved EF (HF-PEF) is more challenging. The aim of the study was to assess the prevalence of HF-PEF among patients hospitalized for HF, to evaluate the pertinence of HF-PEF diagnosis and to compare HF-PEF and HF-REF patients with respect to outcomes. The analysis included 661 Polish patients hospitalized for HF, selected from the European Society of Cardiology (ESC)-HF Long-Term Registry. Patients with an EF of ≥50% were included in the HF-PEF group and patients with an EF of <50% - in the HF-REF group. The primary end point was all-cause death at 1 year. The secondary end point was a composite of all-cause death and rehospitalization for HF at 1 year. HF-PEF was present in 187 patients (28%). Of those 187 patients, mitral inflow pattern was echocardiographically assessed in 116 patients (62%) and classified as restrictive/pseudonormal in 37 patients (20%). Compared with HF-REF subjects, patients with HF-PEF were older, more often female, and had a higher prevalence of hypertension, atrial fibrillation and sleep apnea. Despite lower B-type natriuretic peptide concentrations and lower prevalence of moderate-to-severe mitral regurgitation in patients with HF-PEF, congestive symptoms at admission were as severe as in patients with HF-REF. There were no significant differences in in-hospital mortality between the HF groups. One-year mortality was high in both groups (17% in HF-PEF vs 21% in HF-REF, p = 0.22). There was a trend toward a lower frequency of the secondary end point in the HF-PEF group (32% vs 40%, p = 0.07). In conclusion, in clinical practice, even easily obtainable echocardiographic indexes of diastolic dysfunction are relatively rarely acquired. One-year survival rate of patients with HF-PEF is not significantly better than that of patients with HF-REF.