The role of left ventricular (LV) diastolic function in health and disease is still incompletely understood and under appreciated by most primary care physicians and many cardiologists. Physical examination, electrocardiogram, and chest radiographs are unreliable in making the diagnosis of LV diastolic dysfunction in most individuals, and invasive measurements of cardiac pressures, rates of LV relaxation, and LV compliance are costly, clinically impracticable as they carry increased risk, and require special catheters and software analysis programs. The authors address the definition of LV diastolic dysfunction, history of diastole, LV filling patterns, pulmonary venous flow velocity variables, additional ancillary data, practical echo-Doppler evaluation of LV diastolic function, and limitations.