The collection brings together scholars from Public Policy and Foreign Policy to address the theme of policy fiascos. So far research on failure and fiascos in both Public Policy and Foreign Policy has existed independent of each other with very little communication between the two sub-disciplines. The contributions aims to bridge this divide and bring the two sides into a dialogue on some of the central issues in the study of fiascos including how to define, identify and measure policy failure (and success); the social and political contestation about what counts as policy fiascos; the causes of policy fiascos and their consequences; the attribution of blame; as well as processes of learning from fiascos. A common theme of the collection will be to explore different epistemological and methodological approaches to studying policy fiascos. The volume appeals to scholars and practitioners interested in policy failures and fiascos both within and among states and other international actors. This book was previously published as a special issue of the Journal of European Public Policy.