In this paper we analyse, through the instrument of the social network analysis, the network of co-authorships in the publications of the firms belonging to the Italian life-science biotech sector. We identify the kind of institutions the authors of the publications are affiliated to (we divide the institutions in universities, research centres, hospitals and firms), then we observe the role of the different institutions inside such network. The analysis shows the central role of the universities but also the importance of hospitals, frequent partners in publications, and of the research centres for their "bridging" role between different institutions. © Springer-Verlag Berlin Heidelberg 201