Research which focuses on children's perspectives of their well-being complements and challenges existing research and policy on children. The study reported on here explored children's views of what constitutes well-being, what meaning children and young people ascribe to the concept and whether distinct dimensions or characteristics of well-being can be identified. The project was initiated by the New South Wales Commission for Children and Young People as a basis for developing an authoritative child-informed framework for monitoring of well-being of children in New South Wales, Australia. In this paper, we outline the rationale for and details of qualitative research methods employed in the project, along with details of the major findings from the research. These include, the overarching importance of relationships with others and, more specifically, the importance of agency and control in the various domains identified as relevant to their wellbeing, the importance of safety and security and the way these factors contribute to sense of self. More minor but significant domains identified were: dealing with adversity, material and economic resources, physical environments, physical health and social and moral responsibility. The significance of the findings for policy development and the particular challenge of developing indicators from the research are discussed.