Rates of mental health difficulties were investigated among children in substitute care across five childcare teams in Craigavon and Banbridge H+SS Trust. A total of 64 children were assessed using a behavioural screening instrument. Results indicate that more than 60% of 4-10 year olds assessed may have a diagnosable psychiatric disorder. The presence of such a disorder is probable in almost 50%. Among the 11-16 year olds assessed, the proportion likely to have a diagnosable disorder is slightly higher at almost two-thirds of the sample group. A significant number of children appeared in more than one diagnostic category, indicating the complexity of their presentation and probable co-morbid diagnoses. The implications of these results for further research and for the provision of mental health services to young people in substitute care are discussed. (Contains 6 tables and 3 figures.)