A most significant life event in the first years of life is a disease, especially if it is of early onset, severe, life threatening, with an uncertain prognosis, and with the necessity of frequent diagnostic and therapeutic interventions. Psychological implications are a significant parts of the illness, not a marginal component; they can affect prognosis and outcome. The authors describe the different psychological implications of an experience of chronic disease in children and adolescents and their families (parents and siblings). Congenital disease (for example congenital heart failure) has a peculiar significance: since it is diagnosed early, it influences mother-infant interactions from the beginning, in a crucial moment of the infant's psychological development; diagnostic and therapeutical interventions are early and frequent; congenital defects determine the strongest guilt feelings in the parents. Some specific psychological aspects can be described: the weakening of the Bodily self, the inhibition of thinking, the theories the child and the family formulates on the disease, the death feelings. Emotional features in children and adolescents with congenital cardiopathy are described: inhibition of emotions, marked anxiety, depressive reaction, with loneliness, low self-esteem and inadequacy, emotional lability, with oscillation between omnipotence and inadequacy; impulsiveness; weakness of self identity; especially in bodily Self. Some psychopathological aspects in children and adolescents with heart transplant and their families are also described. Intellectual level of patients with congenital heart disease is in the normal range, although significantly lower than normal controls. There is a positive correlation between worsening of intellectual functioning and clinical severity of the heart disease; this clinical severity is related both to restrictions in normal daily life activities, and blood oxygen saturation. It is hard to tease apart the role of early physical limitations versus the role of chronic hypoxia, in affecting intellectual development. Some methodological considerations are described, relating to the role of the physician, the psychological support to the children and adolescents and their families, the problem of the shared-cares between main centres and local hospitals, where primary health-care team operates.