Despite the growing significance attached to knowledge production, innovation, commercialisation, and ‘third stream’ knowledge exchange activities between universities and business, we know little about how, under what conditions and with what consequences, intermediary organisations — like university incubators and their managers — strategically manage their knowledge ‘brokerage’ (Meyer, 2010) or ‗mediation‘ (Osborne, 2004) roles so as to promote the flow of ideas across university-business boundaries. To investigate these processes, we examine four hi-tech incubators, established in 2002, making up the SETsquared Partnership between four universities (Universities of Bath, Bristol, Southampton and Surrey) in Southern England. These university incubators act as ‘boundary spanners’, hoping to create new linkages and opportunities for sharing and learning between the university and the economy of the wider city-region. This paper reports on the aims, scope and outcomes of these incubators, focusing particularly on the knowledge mediation strategies of the Incubator Directors. We show how each SETsquared partner university has developed its own unique incubation centre and repertoire of knowledge mediation strategies; the result of wider institutional arrangements and mechanisms, on the one hand, and internal incentives and interests/capabilities of the key personnel, on the other. We identify a range of knowledge mediation strategies deployed by the incubator Directors as they enact the incubation process, such as trend spotting, talent spotting, ideas spotting and resource spotting.