Theories of policy processes are typically underpinned by assumptions of bounded rationality in which only a fraction of the available information on a policy issue can be absorbed, comprehended, included, and communicated by any given policy community. From a scientific point of view, this boundedness is convenient, as it helps policy process scholars identify actors, define the problem, and frame a narrative. The problem is that some of the major current policy issues, such as climate change, food production, and migration, are wicked problems that cannot be resolved within limited boundedness—they are simply too big and globally interconnected. A question that comes to mind is to what extent existing policy-process theories are equipped to analyse such significant policy challenges. This paper discusses some of the inherent conceptual and operationalisation challenges in the study of wicked problems and policy processes. On the empirical side, I pay particular attention to administrative, political, and technical aspects characterising wicked problems as well as challenges related to public expectations and communication. As an illustration, I use ongoing work for the UN on the uptake of scientific knowledge in policies on disaster risk reduction.