This article introduces the Special Section Evaluation, International Organizations, and Global Policy. It provides a synopsis of the overarching challenges and opportunities for evaluation in the field of global public policy through international organizations. In the article four issue areas are addressed. First, is the central role of peacekeeping, development, and environment in global public policy and how evaluations enhance the governance capacity of international organizations in these areas. Second, the contribution that evaluation can make toward legitimizing the activities of international organizations through accountability mechanisms of communication, assessment, and optimization of outcomes. Third, how evaluation at the international level is especially suited to facilitate solutions to increasingly complex and globally interdependent problems. Fourth, it concludes with, how evaluation contributes to producing constructive policy at the global level. This includes, especially in terms of policy implications, the need to evaluate evaluation itself on a regular basis, in order to ensure its constant progress as a discipline and practice, and the need to embed evaluation in good policies, at the global level among others.