This chapter highlights the challenges of integrating health and social care from an economic perspective and the difficulties of undertaking economic evaluation in this area. The development of primary care trusts offers opportunities for integrating health and social care budgets. However, in many areas, the two cultures are very different and will inevitably pose a number of problems for decision makers. The chapter focuses on these three themes in a UK context. First, however, it is important to be clear what is meant by social care and how it relates to health and healthcare. The chapter addresses the cultural, governance and outcome conceptualisation issues with some of the associated challenges for health economists and commissioners as they seek to capitalise on the opportunities that interagency working offer. Social care shares many features with healthcare, although in this chapter the authors have focused on areas of difference.