The mitral apparatus is complex and comprises the left atrium, left ventricle, mitral annulus, and leaflets. 3D echo is the diagnostic technique that has contributed most to our knowledge of mitral valve anatomy and function. Since mitral regurgitation (MR) augments negative remodeling, which can be reversed by early repair, accurate quantification of MR severity plays an important role in decision-making regarding how to repair, how early to repair the valve, and if transcatheter mitral valve therapies can be used to repair the valve. Real-time three-dimensional transesophageal echocardiography correctly recognized surgical-validated mitral valve prolapse anatomy in 92% of patients versus 78% of patients using 2D echo. The MitraClip is currently the only US Food and Drug Administration approved device for transcatheter mitral valve repair.