This chapter analyses the type of interactions between the International Labour Office – the permanent secretariat of the International Labour Organization (ILO) – and migrant-protection associations grouped together under the umbrella organization the Permanent Conference for the Protection of Migrants (CPPM) as well as the consequences of those interactions. It examines those key players in the internationalization of the issue of social protection for migrants, their resources, practices and relations as well as both the constraints imposed and the opportunities afforded by the institutional framework and by international events. The analysis highlights the multi-positional role of International Labour Office staff, who were often involved in both private and public organizations as well as the importance of committees and conferences as occasions for networking and uniting forces. It examines how the Office established a division of labour in order to progress towards its goal of regulating international migrations. It delves into how private organizations were led to create new, depoliticized fields of expertise, addressing issues both from a moral standpoint and with a technical approach. Finally, the chapter also shows private organizations’ determination to be involved in migration policies as suppliers of social services, thus participating in defining the migrant-protection cause.