This paper argues that the concept of social accountability can be useful to explain the transparency and accountability policies adopted by international organizations (IOs). Social accountability is understood as the contributions of civil society actors in the functioning of IOs. In international politics, the recent development of IOs' accountability mechanisms has been challenged by the absence of a world government and the impact of inter-state power relations on the decision-making process of international organizations. The presence of civil society actors can reduce the gap between international organizations and citizens affected by their activities. This article resorts to a specific case study: the World Bank Inspection Panel. The analysis revealed the role of civil society actors in the creation, operation and outcomes of this institution. This analysis shows that the concept of social accountability can be adequate to explain not only the Inspection Panel, but other mechanisms recently developed by international organizations.