Children in foster care often have no means of influencing matters that concern them, and can easily become outsiders in their own lives. The United Nations Convention on the Rights of the Child enshrines the rights of capable children to express their views freely in matters affecting them and to be heard in any judicial or administrative proceedings concerning them. The aim of this study is to analyse foster children's participation in child welfare processes in different time periods and contexts from the perspective of children and social workers. The data comprise semi-structured interviews of eight children and young people aged seven to 17 in family foster care, as well as interviews of four child welfare social workers. Ethical questions were taken carefully into account. The results suggest that participation in matters concerning them is very significant to children, although they do not always want be active participants (e.g. in meetings). The children hoped that social workers would take a genuine interest in them, listen to them and take their opinions and wishes into consideration. Children sought true and essential information about the reasons for placements and the plans for their future. They felt they were better heard and more able to influence their own affairs after being placed in a foster home than during earlier phases of services. The study identifies many obstacles in children's participation at different systemic levels. Children's loyalty to their parents may prevent them from expressing their opinions. According to social workers, the most serious obstacles in participatory work with children are related to a lack of human and time resources. Social workers need time, work practices, skills and practical wisdom through which children's personal experiences, opinions and wishes can be better heard. They also seek support in handling the emotional aspects of child-protection work and suggest some other measures to develop their work. (Contains 1 table and 3 figures.)