The �knowledge economy� is now widely debated and economic geographers have made a significant contribution to understanding of the influences upon the production and dissemination of tacit knowledge within and between firms. However, the continued association of tacit knowledge with practices rooted at the local scale and suggestions of territorially sticky knowledges has proven controversial. Through examination of empirical material exploring the stretching of learning in advertising professional service firms, the paper argues that we need to recognise the use of two different epistemologies of organizational knowledge leverage - �knowledge transfer� in the form of best practice and �the social production of new knowledge� - and their complementary yet differentiated roles in organizations and differing spatial reaches. This highlights the existence of multiple geographies of tacit knowledge and the need to be more subtle in our arguments about its geographies. In particular, the paper reveals that tacit knowledge can have global geographies when knowledge management practices focus on reproducing rather than transferring knowledge across space.