Conventional two-dimensional and Doppler echocardiography (2DE) are widely used to establish the pathophysiology and to assess the severity of aortic regurgitation. However, due to its tomographic nature, 2DE has important limitations to appreciate the geometry and the dynamics of the aortic valve complex. Conversely, three-dimensional echocardiography (3DE) can assess the aortic valve complex without geometrical assumptions about the shape of its different components and offer unprecedented, anatomically sound, images of the aortic valve. The different components of the aortic valve complex can be visualized from any perspective using a single acquired full-volume data set allowing a complete understanding of their anatomy and function. The following chapter describes the additional value of 3DE over 2DE for the assessment of patients with aortic valve regurgitation, with respect to etiology, mechanisms and severity of the disease, as well as planning of future procedures.