Recent years have seen the emergence, take-up and use of the term 'policy mix' by innovation policy makers and by policy analysts and scholars alike. Imported from economic policy debates, the term implies a focus on the interactions and interdependencies between different policies as they affect the extent to which intended policy outcomes are achieved. However the meaning of the term remains ambiguous. Nonetheless, we argue that the emergence of the 'policy mix' concept into common use in the field of innovation policy studies provides us with a window of opportunity to reconsider some basic and often hidden assumptions in order to better deal with a messy and complex, multi-level, multi-actor reality. We draw upon a range of literatures to re-conceptualise the basic building blocks of innovation policy studies in order to arrive at a useful definition of 'policy mix' tensions and interactions of different kinds across a series of dimensions. We suggest that this reconceptualisation has important implications for the future scope and focus of prescriptive and analytical innovation policy studies. © 2011 Elsevier B.V.