The Montreux Document is an intergovernmental initiative, launched cooperatively by Switzerland and the International Committee of the Red Cross, to promote respect for international humanitarian law and human rights law whenever private military and security companies (PMSCs) are present in armed conflicts. The study addresses two interrelated objectives: it provides food for thought to inform discussions during the Montreux+5 Conference; and, it identifies concrete ways in which the Montreux Document can advance implementation of PMSC regulation at the national level. The report provides an overview of states’ experiences in this area, discerns major challenges in implementation, and identifies ways to build on existing good practices in the future. The study also focuses on the way forward by proposing concrete ways that the Montreux Document can serve as a force multiplier for effective implementation of PMSC regulation at the national level.