This chapter will set out a sociological approach to complementary and alternative medicine (CAM) in Western societies in general and Britain in particular, with a focus on power and professionalisation in CAM. Too often, this latter concept is seen statically in terms of a group of specific therapies, which are frequently viewed as either traditionally or holistically based. Aside from the fact that only some CAM therapies have long historical roots or take a whole-person approach philosophically and in their practical orientation to the client (see, for example, Coward 1989), developing a definition based on a fixed cluster of therapies does not capture the dynamic nature of CAM in the West. This is best conceptualised as fluidly related to orthodox medicine – the boundaries of both of which are interlinked and change over time (Saks 2003). CAM is therefore defined here in terms of its subordinated position in relation to orthodox health care, centred on the marginality of CAM practitioners in relation to power in the occupational division of labour.