This article examines the transesophageal echocardiographic assessment of the left atrial appendage anatomy and function in individuals without significant structural heart disease and in those with atrial fibrillation with or without cardioembolism or mitral valve stenosis. We also summarize the available data in the usefulness of transesophageal echocardiographic studies in patients undergoing cardioversion for atrial fibrillation and percutaneous balloon valvuloplasty for mitral stenosis. Also, potential limitations and ongoing developments in the use of transesophageal echocardiography in the assessment of the left atrial appendage are outlined, and recommendations are given for the uniform reporting of quantitative data.