Congenital heart disease can be a diagnostic challenge. Transesophageal echocardiography (TEE) has markedly extended the diagnostic power of the ultrasound examination. Outpatient TEE is most useful in the assessment of adult congenital heart disease. Outside the acute care setting, TEE is not commonly used to diagnose pediatric congenital heart disease. Most anomalies can be accurately assessed with transthoracic echocardiography. In the intensive care unit, cardiac catheterization laboratory, and operating room, TEE is used in patients of all ages to assess the anatomic and functional spectrum of preoperative and postoperative congenital heart disease. A consistent anatomic presentation is used to show various congenital cardiac anomalies.