Preoperative evaluation of a 12-year-old girl, previously diagnosed as having a coarctation of the aorta, revealed a rare form of isolated interruption of the aortic arch. Two-dimensional echocardiography played an important role in the delineation of the defect and significantly reduced the need for invasive techniques. It helped to anticipate problems in reaching left-sided structures at cardiac catheterization, saving time and unnecessary trauma. This technique also ruled out associated intracardiac anomalies that were not detailed at cardiac catheterization.