‘Quality’ is now high on the policy agenda for many of our major public services. This article raises the question of what are the respective roles in securing quality of, on the one hand, professional service deliverers and, on the other, managers. It reviews a range of possible roles for managers and concludes that some of these are likely to be illegitimate and ineffective. Even the more appropriate roles will, however, often prove difficult to establish in practice. The article concludes with an examination of some possible key design features for successful relationships between managers and professional service deliverers. These are examined against the background of specific changes currently underway in the health care and education sectors.