Transesophageal echocardiography (TEE) has opened a new window to the heart not only in adult cardiac surgery but in pediatric cardiac surgery. Its success rate in clinical decision making is impressive. It has become an important part of pediatric and adult cardiology. The combination of unique morphological and hemodynamic information of exceptional diagnostic quality and the possibility to use this diagnostic method as a bedside tool in the intensive care unit and the operating room guarantee that this diagnostic modality will maintain its firm place in the diagnostic armamentarium of cardiologists and anesthesiologists. TEE can provide an immediate gauge of surgical results and can be of help to avoid suboptimal surgical outcomes. We showed a recent advance with TEE modality including 3D TEE.