The increasing number of adult patients with congenital heart disease and the better survival of patients with complex disease into adulthood, as a result of the success of pediatric cardiology and cardiac surgery over the last years, have increased the need for specific structures, the so-called grown-up congenital heart disease units, able to provide comprehensive care to these patients. Many of the adult patients with congenital heart disease will require, over time, further operations, urgent in-hospital admission for a wide range of complications such as arrhythmias, hemorrhage, heart failure and bacterial endocarditis. Furthermore, these patients may often experience despair due to their awareness of residual morbidities and the knowledge of possible early mortality, or limitations in their social lives and educational or occupational attainment. Provision of care for children with congenital heart disease is well established in most parts of the world. In contrast, clinical services for the adults with congenital heart disease are scarce. In this scenario, adult cardiologists are not always equipped to deal with the range ad complexity of grown-up patients with congenital heart disease, whereas pediatric cardiologists cannot be expected to manage the many acquired adult diseases in a pediatric medical environment.