Abstract Chapter 6 examines the employment of private military and security contractors in situations of armed conflict. The use of private military and security contractors or PMSCs has contributed to a blurring of the civilian-military distinction that the modern law of armed conflict is built around, and creates its own problems for both those parties to a conflict who employ PMSCs, and those who find themselves confronting PMSCs and the States (or non-State groups) who employ them. This chapter explores the problems that arise regarding the use of PMSCs in war zones, analyses their status under IHL, and examines how their use creates significant problems for all parties in times of armed conflict.