The Cardiology division provides comprehensive care for children with heart disease and is conducting novel research to improve diagnostic and treatment modalities for the future. There are fifteen board-certified pediatric cardiologists in the division, each with a special area of expertise including critical care medicine, interventional catheterization, electrophysiology, advanced imaging, cardiac transplantation, heart failure, prevention, and adults with congenital heart disease. The Division provides services at Children’s Medical Center Dallas and Children’s Medical Center Legacy in outpatient clinics (~7,000 visits/year), a 22-bed inpatient telemetry floor dedicated to cardiac patients, a 21-bed dedicated Cardiac Intensive Care Unit, two catheterization laboratories for diagnostic and interventional procedures including catheter ablation, and an echocardiography suite, including special areas for fetal echocardiography, as well as a complete non invasive monitoring laboratory. The Division has one of the most active heart transplantation programs in the country. Together with our surgical colleagues, we cared for children having over 350 open-heart surgeries in 2008. In addition to the full range of clinical activities, the Division has numerous prominent prospective clinical trials ongoing or recently completed. Finally, we have been at the forefront of understanding the genetic control of congenital heart defects.