Diastolic dysfunction plays an important role in the pathophysiology of heart failure. Although it is still controversial whether or not patients with preserved ejection fraction have depressed left ventricular (LV) systolic function, LV filling pressures determine exercise tolerance independent of the severity of systolic dysfunction. Therefore, estimation of LV filling pressures is important not only for diagnosis, but also for management of patients with heart failure. The efficacy and limitations of different diagnostic approaches, including Doppler imaging, are discussed.