The relative impact of comorbidities and parameters of left ventricular diastolic function on clinical outcome has not been thoroughly investigated in patients who are hospitalized for heart failure decompensation and found to have preserved ejection fraction. We identified 98 HFpEF patients among 1452 patients admitted with acute heart failure. Clinical characteristics, hemoglobin levels, estimated glomerular filtration rate (eGFR), B-type natriuretic peptide (BNP) and Doppler-echocardiographic parameters were analyzed. The primary end point of the study combined death and rehospitalization for decompensated heart failure after the index hospitalization. Mean age was 76 ± 9 years. LV ejection fraction, E/E _a ratio, and estimated systolic pulmonary artery pressure were 61 (55–67)%, 12.9 (9.4–15.1), 40 (32–46) mmHg, respectively. BNP values, hemoglobin and eGFR were 287 (164–562) pg/mL, 11.3 (10.4–12.4) g/dL and 45 (37–74) mL/min/m², respectively. During a mean follow-up of 17 ± 11 months, 56% reached the primary endpoint of the study: 31 died and 24 were re-hospitalizated for heart failure. Diabetes [HR = 1.76 (1.03–3.00), P = 0.039], lower systolic blood pressure [HR = 0.99 (0.97–0.99), P = 0.016], hemoglobin [HR = 0.62 (0.49–0.76), P < 0.0001], and eGFR [HR = 0.98 (0.97–0.99), P = 0.004] were associated with a poor outcome. Neither BNP nor echocardiographic parameters were correlated with outcome. Comorbidities primarily correlate with outcome in patients with HFpEF.