The evaluation of left ventricular (LV) diastolic function is an essential component of the echocardiographic examination for dyspneic patients with impaired or preserved LV systolic function. Doppler echocardiography in combination with two-dimensional echocardiographic findings can assist the diagnosis of underlying cardiac dysfunction, give an estimate of LV filling pressures, guide heart failure treatment, and provide important prognostic information. This article reviews the essentials of modern Doppler assessment of diastolic function and highlights recent updates, areas of controversy, and future applications.