4DE (i.e., dynamic three-dimensional) echocardiography is a new developing technique in recent years. Inour study, a three-dimensional echo scan computer system was used to acquire and store the two-dimensional information, then to reconstruct the stereoscopic image of the heart according to its space-time continuum. It can yield a better approach, which can help identify the various structures of the heart and great arteries and facilitate understanding of spatial relations and motion. In addition, it can display physiologic information such as the direction, course, size, and shape of the blood flow. We have examined 138 patients by both trans-thoracic and transesophageal approaches. Our preliminary experience shows that 4DE is of great value in diagnosing congenital heart disease and valvular disease.