Multidimensional treatment foster care (MTFC) is an intervention for looked after children and young people with complex needs who are already displaying severe levels of challenging and antisocial behaviour or who are experiencing high levels of placement instability. The first grant-funded pilot programmes were developed for adolescents and have been followed by those for younger children. The programme for adolescents is being rigorously evaluated through a randomised controlled trial (RCT). This is a complex evaluation as it is one of the first such trials to be conducted in services for looked after children and will report early in 2010. It will help us establish whether this treatment intervention is more effective and cost-effective than services as usual for this very vulnerable group of looked after children. Depending on the findings we will consider what further capacity should be developed to meet the needs of looked after children and young people. While waiting for the evaluation results we are conducting an annual audit of progress to provide feedback to pilot sites and learn from experiences to date.