As with adults, the quality of life of children is a multi-dimensional concept, therefore, in theory, evaluations cannot be carried out except by the subject, given the very subjective nature of this procedure. There are obstacles in pediatrics with this postulate, as one would prefer to implement a procedure of evaluation regarding the child's own characteristics in order to determine the cognitive limits of his/her development. We have attempted to summarize this subjective aspect by adapting tools for evaluation suitable for both the child and adolescent. 1) The AUQUEL questionnaire. Targeted to nursery school or primary school children, it consists of a closed scale comprised of thirty-one items: the phases of satisfaction are presented with the use of four aspects which express different emotional conditions. It also includes an open question. 894 French children so far have filled out this questionnaire: 491 from the general population, 403 were evaluated under specific contexts, either organic illnesses, psychological problems, or in the context of social personalities. Differences can be observed, depending on the contexts, in a closed scale or an open question. We will look at the example of a kidney transplant to illustrate our point. 2) The "OKadolescent" questionnaire Similar in structure to an adult questionnaire; it differs, however, by the themes that are adopted to the life and preoccupations of an adolescent. It is made up, as with the questionnaire for children, of a closed scale (26 items), and an open question. Here, 268 adolescents from the general population can be compared with adolescents evaluated in either a somatic or war-zone context. We will take as an example adolescents who have undergone kidney transplants or have suffered from hepatitis, to demonstrate the paradoxical characteristics of the evaluation of the adolescents quality of life. 3) Conclusion Our experience in this domain of the evaluation of a child's quality of life enables us to confirm its feasibility, on the condition of using specific tools, for the clinician (the best representation for the impact of pathology on a child's quality of life), and its relevance as an element for evaluating the needs linked with the health of the given population.