The aim of this study is to describe structural characteristics and staff resources of child psychiatric and adolescent psychiatric hospital wards in Finland. The target group of the survey consisted of 69 child and adolescent psychiatric hospital units in Finland. Information was obtained from 64 units (93%). Most of the wards were based on 24-h-a-day provision. There were only 7-day-treatment programmes including two family wards. When compared internationally, the numbers of units, beds and staff levels were high in Finland, with all members of staff qualified. The nurse-patient ratio and psychiatrist resources were rather satisfactory. However, in many units there was a lack of psychologists, social workers and occupational therapists. General recommendations and guidelines for staff resources in child and adolescent hospital treatment wards are warranted.