This article sets the scene for the other papers in this Special Issue on children's and young people's participation, by outlining the nature of the ESRC Seminar Series from which all are derived and by developing the main themes discussed at the seminars. The focus of this Issue is participation by children and young people as this relates to differing notions of social exclusion and inclusion. This article critically examines participation in the contexts of policy, practice, research and theory. In many respects the environments in each of these domains is supportive of increased participation, yet there is also much evidence of limited impact by recent participative measures and of disillusionment by many young people who have been engaged in consultation and decision-making. A way forward is suggested, which entails collaboration among all the key stakeholders including children and young people, connects participatory and social inclusion aims and mechanisms, and is committed to achieving tangible outcomes based on the wishes of children and young people.