Participation is in the International Classification of functioning, disability and health – children and youth version (ICF-CY) defined as “involvement in a life situation”. Participation includes two dimensions; being there and being involved/engaged while being there. These two dimensions of participation are applicable on children’s engagement in everyday activities, families and childen’s engagement in interventions and professional’s way of collaborating with children and families. Participation can be viewed as a transactional phenomenon in that engagement elicits interest in other children and adults/professionals. Their interest in turn leads to that the child in need of special support is invited to engaging experiences. Thus, participation is a pivotal process that generate a positive upward spiral not only in children but also in families and professionals. Implications for concepts used, measures and interventions will be discussed.