This article argues that the literatures on policy transfer and policy diffusion are complimentary, but need to focus more clearly on five key issues drawing insights from both literatures. First, work in each area can benefit from a greater focus on the changing interactions between the various mechanisms involved in diffusion/transfer. Second, the diffusion literature privileges structure, while the transfer literature privileges agency, but we need an approach which recognizes the dialectical relationship between the two. Third, the diffusion literature concentrates on pattern-finding, while the transfer literature examines process-tracing, but any full explanation of transfer/diffusion needs to do both. Fourth, both literatures suffer from skewed case selection with, in particular, too little attention paid to developing countries. Finally, while both literatures need to be interested in whether diffusion/transfer is likely to be successful/unsuccessful, neither considers any criteria that might be used to establish policy success and failure.