From the experience of chronically ill children, this article proposes to report some ambiguities existing in the notion of agency and in its application to childhood. Focusing on a ‘competence paradigm’, studies on childhood seek to take children seriously as social agents in their own right and to demonstrate their active participation and competences in the different social con-texts they live in. Nevertheless, if children sometimes want to be seen as actively engaged and competent, we will see from the point of view of chronically ill children that they do not nec-essarily express their agency in this unique way nor want to be competent in any situation and at any time. In a manner which is not always visible to adults, children might also express their agency through silences, withdrawals and other non-participatory ways.
Keywords: Childhood; Agency; Participation; Competence; Chronic illness; Type 1 diabetes.