Down syndrome is the commonest occurring syndrome, and because of the high risk of congenital heart disease, these children are frequently seen at cardiology clinics and wards. However, these individuals are also likely to have a variety of other-problems, both congenital and acquired, which may impinge on the medical and surgical management of cardiac problems. It is therefore important for the paediatric cardiology community to maintain a minimum level of expertise in other noncardiac aspects of the syndrome. This paper reviews Down syndrome, lists congenital and acquire disorders that may occur, and briefly addresses recent advances in the understanding of this condition.