The participation of service users in the planning and delivery of social work services has become a familiar objective in the UK. Policy injunctions, however, mask a lack of clarity around what is meant by terms such as ‘participation’ and ‘engagement’. Moreover, since many service users do not engage with social workers voluntarily, the expectation that they become centrally involved in the planning and delivery of services highlights tensions and contradictions. This article explores social work engagement with involuntary clients, drawing on findings from a knowledge exchange project involving academics and local authority social workers. A review of the literature traces the background to user involvement and identifies its different s...