The recognition of children's social agency and active participation in research has significantly changed children's position within the human and social sciences and led to a weakening of taken-for-granted assumptions found in more conventional approaches to child research. In order to hear the voices of children in the representation of their own lives it is important to employ research practices such as reflexivity and dialogue. These enable researchers to enter into children's "cultures of communication." Drawing on detailed examples from an ethnographic study on child health and self-care, the article examines issues of power, voice and representation central to the discussion of children's participation.