Based on a presentation from the Millennium Festival of Medicine The idea that a single hospital can provide all the facilities necessary for its catchment area is no longer tenable. In 1998 the Scottish acute services review recognised this and proposed the development of managed clinical networks as an innovative way of providing acute services in the NHS in Scotland.1 We describe here the characteristics of these networks. Managed clinical networks are linked groups of health professionals and organisations from primary, secondary, and tertiary care, working in a coordinated manner that is not constrained by existing organisational or professional boundaries to ensure equitable provision of high quality, clinically effective care. Networks can be of several types—for example, they can cover a specific disease, such as peripheral vascular disease; a specific specialty, such as neurology; or a specific function, such as medical receiving. The term network might suggest diffused responsibility, but these networks are not casual or informal: the point is that they are managed. The core principles of a managed clinical network were set out by the Scottish Office department of health management executive in 1999.2 They include: