The use of external policy consultants in government has been an increasing focus of concern among governments in the U.S., the UK, Canada and Australia, among others. Concern has arisen over the costs incurred by governments in this area and over the possible rise of a ‘consultocracy’ with the corresponding diminishment of democratic practices and public direction of policy and administrative development that could entail. However, current understanding of the origins and significance of the use of policy consultants in modern government is; poor with some seeing this development as part of a shift in the overall nature of state-societal relations to the ‘service’ or ‘franchise’ state and away from the ‘positive’ or ‘regulatory’ state, while others see it as a less significant activity linked to the normal development of policy advice systems in modern government. This article surveys the existing literature on the phenomena, in general, and identifies several methodological and data-ralated issues germane to the study and understanding of the activities of this set of external policy advisory system actors.