Foster care has become the principal placement of choice for children and young people in public care in the United Kingdom (UK). This has been accompanied by a significant growth in its research scrutiny connected to a busy policy agenda, especially since 1997. With its increased usage, fostering has encountered both difficulties and developments. Children often have emotional and behavioural problems which strain their foster families to their limits and risk placement breakdown. Public sector foster carers continue to be in short supply and keeping them engaged in fostering remains a challenge. Major developments have occurred in response to these difficulties. The use of relatives as kinship carers has increased substantially and the non-governmental or independent fostering sector has grown rapidly. Until comparatively recently, the knowledge base of foster care in Britain was limited, but the past decade has seen that change and now a substantial body of research knowledge is available in the UK.