It has been estimated that 9 to 13% of children and adolescents have a mental disorder that causes significant functioning impairment and that only one fifth of those who need mental health services actually receive them. The majority of children and adolescents are enrolled in schools, where they spend a considerable amount of time, and this is followed by the increasing efforts to establish collaboration between mental health professionals and school personnel. The role of mental health professionals is crucial in improving children's mental health, as well as for providing better response to parents, educational staff and other agencies. There are several ways for a child psychiatrist to reach children and adolescents in a school setting: through individual student consultations (case consultations), through consultations to schools on general mental issues (systems consultations) and through promotion of mental health by creating and demonstrating evidence-based programmes for children, parents, school staff and others who are involved in child's care. In order to achieve these goals, we need to establish partnerships and to define roles among organisations and individuals in the wider school environment, such as schools and school management, municipal authorities and administration, media, police, social welfare centres, health centres, parents and youth associations.