International Governmental Organizations (IGOs) have received important attention in the field of International Relations (IR). However, several apparent inconsistencies or “anomalies” have emerged as areas of concern for the discipline. These include the need for discretion in the management of IGOs, the accountability issues that arise from their decisions and actions, the degree of autonomy they possess, the power they can wield over states, the regulatory influence they can exert, and their ability to transcend the sovereignty of individual states. Despite this, the agency of individuals within IGOs and the agency of IGOs remain difficult to understand. This is particularly challenging given that IGOs are supposed to be subordinate to the power and decision-making of the states that establish them, yet they require a certain level of autonomy to be effective. This chapter provides a brief overview of the IR perspective on IGOs and discusses the most significant anomalies identified in IR studies of IGOs. It is observed that several of these anomalies can be explained by incorporating knowledge from organizational theories.