This paper addresses the strategies adopted by science-based start-ups to gain access to knowledge resources at different spatial levels. The goal of the paper is to investigate the presence and relative importance of ties endowed with different types of proximity in firms’ knowledge networks, as well as the role played by non-geographical proximity in gaining access to knowledge sources, both located nearby and at a distance. For this purpose we develop an analytical framework that permits to distinguish between two dimensions of proximity: geographical, associated with the spatial location of the actor; relational, associated with the origin of the tie – leading to different modes of proximity that are further linked with modes of knowledge access (formal or informal). We also develop a methodology to reconstruct the knowledge networks, permitting to identify origin, location and nature of the ties and to position them along modes of proximity. The results show that the incidence and mix of these modes of proximity vary in firms’ individual networks, being possible to identify different patterns of knowledge access. But they also uncover the overall relevance of “relational proximity”, whether or not coexisting with geographical proximity and often compensating for its absence. The paper contributes to our understanding of knowledge access strategies of science-based start-ups and uncovers the spatial spanning role played by the entrepreneurs’ personal networks
