Transesophageal echocardiography (TEE) has emerged as a valuable tool in mitral valve repair, with a role both in surgical decision making and in improving patient outcomes. The anterior part of the mitral annulus has a fibrous structure which is part of the aortic valve and the two trigones. In ischemic mitral regurgitation, a basal anteroposterior annulus diameter greater than 35 mm has a similar negative predictive value, and stress testing is unnecessary. The feasibility of mitral valve repair depends on valve function and morphology. Mitral stenosis is a rare consequence of edge-to-edge techniques. Annular avulsion can occur due to debridement of annular calcification. Wall motion abnormalities in the circumflex coronary artery territory can be a consequence of coronary interruption during annuloplasty. Intraoperative TEE can demonstrate functional valve anatomy and help to elucidate the mechanism of valve dysfunction.