Children in out-of-home care (OOHC) present with high levels of physical, developmental and emotional and behavioural difficulties, yet often fail to receive appropriate services. This article describes a joint health and welfare service specifically developed to provide comprehensive physical, developmental and mental health assessments to a cohort of children entering long-term care in one region of Sydney, New South Wales (NSW), Australia. Paediatric, allied health, dental and psychosocial assessments were co-ordinated from a single referral from the child's welfare case manager. Follow-up appointments were held 6-12 months later to assess the outcomes of recommendations. Physical, mental health and developmental difficulties in the children are reported, the implications for service requirements are presented and process blocks described. There is a need for a specific co-ordinating service to overcome the inherent fragmentation of this group (related both to transience and change in the welfare sector, and levels of comorbidity and chronicity in health presentations). Health and Welfare services must operate together, with an awareness of the processes and resource constraints in each sector, if they are to deliver sustainable and reliable health care to this vulnerable group.