INTRODUCTION Heart failure (HF) is the leading cause of hospitalization in elderly patients. OBJECTIVES The aim of the study was to examine the clinical profile and 1-year outcomes of elderly patients (aged ≥65 years) compared with younger patients (aged <65 years) hospitalized for HF decompensation, as well as clinical differences among elderly patients aged 65-74 years and those aged ≥75 years. PATIENTS AND METHODS The primary endpoint (PE; all-cause death) and the secondary endpoint (SE; all-cause death or rehospitalization for HF worsening) were assessed at 1 year in a group of 765 hospitalized Polish participants of the ESC-HF Long-Term Registry. RESULTS The PE was observed in 9.1% of patients aged <65 years; 18.5% of those aged ≥65 years (P = 0.0001); 14.5% of those aged 65-74 years; and 21.6% of those aged ≥75 years (P = 0.07). The SE occurred in 28.0% of patients aged <65 years; 36.1% of those aged ≥65 years (P = 0.04); 29.2% of those aged 65-74 years; and 41.2% of those aged ≥75 years (P = 0.01). Independent predictors of the PE in patients aged ≥65 years were as follows: chronic obstructive pulmonary disease (COPD), systolic blood pressure (SBP), New York Heart Association (NYHA) class, β-blocker use; in patients aged 65-74 years: coronary revascularization, NYHA class, sodium, and creatinine; in patients aged ≥75 years: NYHA class and SBP. Independent predictors of the SE in patients aged ≥65 years were as follows: COPD, NYHA class, potassium, SBP, and physical activity; in patients aged <65 years: chronic kidney disease (CKD), NYHA, and SBP; in patients aged 65-74 years: NYHA and creatinine; and in patients aged ≥75 years, previous HF hospitalization, coronary artery disease, CKD, COPD, alcohol consumption, smoking, NYHA, and SBP. CONCLUSIONS Elderly patients with HF differed from younger patients in terms of long-term outcome and prognostic factors. There were also important differences within the elderly group itself.