Using our in-hospital experience with chronically ill adolescents, we will try to develop the singularity of a clinical treatment such as we envisage it at « Maison des Adolescents », where every day there are consultations in which pediatricians, child psychiatrists, psychologists and other professionals take part. Taking as an example the situation of Stéphane, a diabetic adolescent of Flemish origins, we will give an outline of our interdisciplinary approach, essentially ecumenical, between practical questions of treatment and the realities of family life.