This document presents a professional view of the optimal organization of congenital heart surgery (CHS) in Europe. It was prepared by the Congenital Heart Disease Committee of the European Association of Cardio-Thoracic Surgery (EACTS) and approved by the European Congenital Heart Surgeons Association (ECHSA). These societies represent the majority of pediatric cardiac surgeons in Europe. Current facilities and arrangements for the care of patients with congenital heart disease are of variable quality throughout Europe. Experience, workload and resources can sometimes be below an adequate level. A structure is foreseen with some large CHS units of high specialization, covering the full spectrum of major and minor surgical procedures such as neonatal surgery, complex repairs, transplantation, and cardiac assist devices. These larger units would also possess research facilities and cater for advanced educational needs within the specialty. They would have an advanced quality assurance system and make their activities and results known to the scientific community. There would also be smaller units of more standard care who most often do not have the full range of activities mentioned above but who would also participate in the same quality assurance system as the larger units. In an optimal structure, the overall surgical activity should be over 250 patients operated per year. This represents a draining area of approximately 4-6 million inhabitants, depending on the birth rate and on the number of foreign patients. In both types of units the organization should be orientated around patient's needs and besides adequate physical and personnel resources, encom-pass such features as: quality control, data collection in a European Registry, risk stratification, reciprocal voluntary audits, individualized surgical results, collaboration in clinical research, continued education and re-certification. The developments suggested in this document will have to be handled differently by each European nation and may take several years to implement as medical policies vary within each country. It should provide useful information and guidance to national governments, regional authorities and health care organizations. The outlined measures are expected to result not only in an improved quality of patient care but also in an improved cost-efficiency of CHS throughout Europe.