Other authors have demonstrated the ability of three-dimensional (3D) echocardiography to produce "en face" views of anomalies such as atrioventricular valve disease and atrial and ventricular septal defects. Few data exist about the usefulness of 3D images for more complex congenital heart defects and the surgical impact of this relatively new technology. This study, covering a period of 8 months and including 43 young patients affected by complex congenital heart defects, demonstrated that the routine use of 3D echocardiography is feasible and valuable for some types of cardiac defects. In fact, 3D images have provided more detailed anatomic definition of interrelations between structures in about one-third (15/43) of our cases, yielding new insight into the anatomy analogous to what can be derived from examining a heart specimen. Our surgeons found the 3D images particularly helpful for providing a realistic and almost specimen-like preview of the surgical anatomy that facilitates planning of the surgical program.