One of the challenges for drug treatment services is how to engage drug users effectively. This commentary examines one particular strategy for enhancing engagement that appears to have spread quite rapidly in recent years: the use of contract-like written agreements between treatment service providers and users. The development of the contractual governance of drug users in treatment is located in the wider context of emerging social control strategies and practices. In particular, insights are drawn from the socio-legal literature which has begun to examine these new control practices in diverse domains. The commentary also reports on the findings of a national survey of all 149 local authority areas in England that was designed to provide a preliminary mapping of the extent of contractual governance in treatment settings (response rate. =. 62%). In spite of the fact that the use of contracts between drug services and service users does not feature in the national drug policy framework, our survey strongly indicates that it is a widespread practice. Although these agreements can take on many different forms, typically they set out the responsibilities and requirements placed on users and, somewhat less frequently, what the service commits to providing for them. This novel practice of contractual governance may be viewed as having considerable potential but it also raises important issues concerning justice and rights. We conclude by arguing that this is an important area of emerging practice which raises significant theoretical and policy questions and the need for further research. © 2013 Elsevier B.V.