Transesophageal echocardiography complements transthoracic examination in 5-10% of patients referred to the echocardiographic laboratory. Clinical indications for performing this procedure are continually evolving. The semi-invasive nature of this procedure necessitates that it be judiciously used and that trained personnel undertake the procedure. Complications of the procedure need to be kept in mind. Future directions in the development of this technology involve newer, multiplanar, multifrequency transducers, digital archiving and retrieval, wide-field imaging, and 3-dimensional reconstruction. For the present, transthoracic echocardiography must remain the primary echocardiographic window imaging the heart, with defined clinical applications for transesophageal echocardiography.