Diastolic dysfunction is a syndrome characterized by impaired ventricular filling. Abnormalities in diastolic function can generally be classified as being the result of abnormal relaxation or of abnormal compliance. Diastolic dysfunction is frequently present in patients with heart failure and it is occasionally the dominant or sole cause of symptoms. It is frequently the result of the convergence of factors such as advanced age, renal dysfunction, left ventricular hypertrophy and impaired coronary perfusion. A good history and physical examination are essential for the diagnosis of diastolic dysfunction. Because it uniquely allows for the noninvasive evaluation of mitral and pulmonary venous flow and provides critical information on the cause of diastolic dysfunction and on associated abnormalities, two-dimensional and Doppler echocardiography is the most useful tool in the comprehensive assessment of diastolic function. Treatment of diastolic dysfunction is difficult and should not only focus on controlling symptoms but also include attempts at resolving the underlying cause. Relief of myocardial ischemia, control of arterial hypertension and regression of ventricular hypertrophy are important objectives of treatment.