One hundred and twenty-eight children with congenital heart disease (CHD) and 89 healthy controls were compared according to their development of personality and intelligence. Presence of physical disability in daily life was the independent variable for dividing children with CHD into two groups: children with physical handicap due to CHD (n = 77) have lower IQ scores than healthy children. Unexpectedly, in the parents' opinion they show no difference in behaviour patterns. On introspective examination, these cardiac patients showed an increased feeling of inferiority and of basic anxiety and a more impetuous behaviour as their way of self-protection, but a reduced need for independence due to parental overprotection was not confirmed. None of these observations could be detected in children with CHD who are physically fit (n = 51).