Abstract. In many cases throughout history, addressing broad political, economic and military tasks involved the use of mercenaries or private military companies (PMCs). They are increasingly used in modern armed conflicts, both local and larger-scale. PMCs are employed to solve a wide range of tasks; their socio-political and power role in advancing various interests, including by means of armed struggle, is growing. The complexity of modern international relations and the increase in economic, technical, informational, political, military and other types of confrontation confirm the relevance of private military companies and the expansion of their influence on social reality. At the same time, the features, characteristics, and patterns of functioning of PMCs have not yet been formulated on an academic level. The experience of conceptualizing the very notion of “private military companies” has not been particularly successful either. Few research works on the PMCs are mainly devoted to the legal basis of their activities, and related bans and restrictions upon them. The present role of PMCs requires conceptualization of this phenomenon by taking into account a complex set of its political, economic, military, security, legal, information, ethical, socio-demographic, social-adaptation and other aspects.