This chapter focuses on the continued relevance of LOAC in situation of armed conflict where PMSCs are used and the regulatory means by which the existing law is being adapted to accommodate the emergence of a new actor. It begins in section 1 with a brief overview of the recent regulatory initiatives that have been designed to address some of the legal problems associated with PMSCs. In section 2, it considers the application of existing LOAC to PMSCs, in particular the status, obligations and accountability of PMSC personnel under LOAC. Section 3 focuses on the obligations and accountability of states, as the primary actors of international law, with respect to the conduct of PMSCs. Finally, section 4 considers the obligations and accountability of the companies themselves.