Cardiac defects form the most frequently encountered group of congenital malformations (0.8%). Despite the improving ultrasonographic technology and the teaching of the investigators, the prenatal recognition of cardiac defects stays low (around 30%). The application of 3D technology in their recognition may well lead to a substantial improvement of this percentage. This technique consists of a consecutive summation of multiple 2D images and permits the three dimensional reconstruction of the different structures and the definition of their spatial position. Its importance is localised in the direct identification of normal anatomy and the possibility to reevaluate the data in an off-line version and if necessary to ask for a specialised second opinion on the same data set, thus opening the door for telemedical approach.