This article looks at the concept of communities of practice (CoPs) in the workplace. The theories surrounding these types of communities are still very new and in the process of development. The practice and the importance of these communities for knowledge transfer are also still to be explored as to the best methods for establishing such communities and how to support and encourage them. Below we discuss the background and main threads of theory that are under development. This is very much a short introduction to the concept. Further discussions can be found in Coakes (2004), Coakes and Clarke (in press), and Lehaney, Clarke, Coakes, and Jack (2003).