While formal decision power in most international organizations rests with the member states, the member states often delegate the preparation of decisions to international secretariats. To prepare decisions, secretariats gather and analyze information and subsequently provide the member states with an assessment on the alternative courses of action. In this process, secretariats may accumulate an information surplus over the member states. They can use this advantage to suggest options close to their own interests. This article argues that, to counter such agency problem, the member states unilaterally invest in shadow bureaucracies with the aim to reduce informational asymmetries. Shadow bureaucracies are, however, costly. Member states have to weigh agency costs against the costs of domestic administrative capability. Strong states with outlier preferences are most likely to invest in shadow bureaucracies. They have most to gain. The use of shadow bureaucracies not only reduces agency costs. It also allows states more control over policy in international organizations. This article uses insights from peacekeeping in the United Nations to illustrate the argument.