Congestive heart failure (CHF) is the leading cause of cardiac morbidity and mortality from cardiovascular disease. Although left ventricular (LV) diastolic dysfunction occurs in all patients with systolic dysfunction and CHF, fully one third of patients have CHF due to isolated diastolic dysfunction. Despite this, the role of diastolic function in heart failure is underappreciated by many primary care physicians and even by cardiologists. Development and validation of several noninvasive Doppler echocardiographic techniques that are relatively load-independent have made echocardiography the clinical standard for the assessment of LV diastolic function. Echocardiography uses portable equipment; is readily accessible and safe; and excludes other causes of CHF, such as valvular heart disease, pericardial disease, and systolic dysfunction. This review summarizes the use of recently developed Doppler techniques for the assessment of LV diastolic function, as well as their application in assessing prognosis and in guiding therapy for various cardiovascular disease states.