Since the end of the 1970s, alternatives to internal government production of public services have assumed increasing prominence. The most important of these has been contracting out, but a less travelled road has been co-production: the involvement of citizens, volunteers and clients in producing public services as well as consuming them. This article focuses on client co-production. It argues that by ignoring this option, governments have closed off one important option in the repertoire of management approaches. It demonstrates the necessity of client co-production to service-delivery and legal compliance, and considers examples of government agencies which have sought to harness it in positive ways.