Background: The patients with heart failure and preserved systolic function (HFPSF) has the high pro B-type natriuretic peptide (proBNP) level and the high ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/Em) derived from tissue Doppler imaging (TDI). Left atrial volume indexed to body surface area (LAVi) has been presumed to reflect chronic diastolic dysfunction. Objectives: We sought to assess the ability of LAVi to reflect left ventricular diastolic dysfunction in comparison with proBNP and E/Em in patients with HFPSF. Methods: 148 patients with stable HFPSF, ejection fraction ��� 50% and proBNP ��� 100 pg/mL underwent conventional echocardiography with assessment of LAVi. Systolic, early and late diastolic mitral annular velocities (Sm, Em and Am) were derived from TDI. Results: In overall patients, the modest correlations were found between proBNP level and Sm (r=-0.215), E/Em (r=0.195) and LAVi (r=0.215). However, in the patients with E/Em ��� 13, LAVi was the most important predictor for determining of proBNP level (r=0.387), whereas in the patients with E/Em < 13, Sm was the most predictor for proBNP level (r=0.285) in stepwise multivariate analysis. Conclusions: In the patients with HFPSF evidenced by high proBNP level, the LAVi would correlate strongly with the proBNP level in the setting of elevated E/Em. However, in those who have low E/Em and high proBNP level, Sm other than the LAVi might be contributing factor in predicting the proBNP level.