Although survival of patients with congenital heart disease has dramatically improved since surgical repair has become available, cure is seldom achieved. Exact data on long-term outcome are not available, however, because a national registry is lacking. Furthermore, little is known about the role of genetic defects in the development of congenital heart disease. The CONCOR-project (CONgenital CORvitia) has been set up to facilitate the investigation of the long-term outcome and molecular basis of specific congenital heart defects and their treatment. It will also facilitate the development of an efficient organisational structure for the improvement of healthcare for patients with congenital heart disease.