The possibility of using private military and security companies to bolster the capacity to undertake intervention for human rights purposes (humanitarian intervention and peacekeeping) has been increasingly debated. The focus of such discussions has, however, largely been on practical issues and the contingent problems posed by private force. By contrast, this article considers the principled case for privatising humanitarian intervention. It focuses on two central issues. First, does outsourcing humanitarian intervention to private military and security companies pose some fundamental, deeper problems in this context, such as an abdication of a state's duties? Second, on the other hand, is there a case for preferring these firms to other, state-based agents of humanitarian intervention? For instance, given a state's duties to their own military personnel, should the use of private military and security contractors be preferred to regular soldiers for humanitarian intervention?