Previous research by Barber and Delfabbro (2004) indicates that approximately 15-20 per cent of young people in Australian out-of-home care have significant emotional and behavioural problems that often condemns them to a life of repeated placement instability and further psychosocial harm. This paper reports the findings of a national comparative study of over 300 children (drawn from South Australia, Queensland, Western Australia and Victoria), all of whom had experienced placement instability due to behavioural problems within the previous 12 months. The study examines their social and family background, psychosocial profile, service history, and current status in each of the care systems. The results provide an opportunity to document the similarities and differences between young people referred for services across the different States, as well as a vehicle for assessing the potential effectiveness and transferability of service responses. Taken as a whole, the results highlight the need for a more integrated national approach to the protection of children with high support needs in Australian out-of-home care.