OBJECTIVE The prognostic impact of right ventricular systolic dysfunction (RVSD) in heart failure (HF) with preserved ejection fraction (HFPEF) is not sufficiently understood. This pilot study evaluates the prevalence and prognostic impact of RVSD in HFPEF. METHODS Ninety-five consecutive patients, admitted due to HF within one year were included and followed up for 12 months. Patients were classified based on left ventricular ejection fraction (LVEF) into two groups: HFPEF (LVEF >40%; n = 54), and heart failure with reduced ejection fraction (HFREF) (LVEF < or = 40%; n = 41). RVSD was defined as peak systolic tricuspid annular velocity (S') <10.8 cm/s. RESULTS The prevalence of RVSD was 22% vs 59%, in HFPEF vs HFREF, respectively (P < 0.001). Patients with HFPEF and RVSD had significantly higher one-year all-cause mortality compared to HFPEF with normal RV function (41.7% vs. 4.8%, P = 0.004). The same trend was found in HFREF (33.3% vs. 5.9%, P = 0.057). A similar outcome was obser ved in cardiovascular mortality (H FPEF 33.3% vs. 0%, P = 0.002 and HFREF 20.8% vs. 0%, P= 0.06). RVSD was the only independent predictor of all-cause one-year mortality in patients with HFPEF (HR 11.5, 95% Cl 2.2 to 59.5, p = 0.004). CONCLUSIONS RVSD is an independent predictor of all-cause mortality in HFPEF. Patients with HFPEF and RVSD had significantly higher one-year all-cause and cardiovascular mortality than those with normal RV function.