The increase in the number of spin-offs has led to the growth of the research to understand the performance of these companies and to assess their impact. The literature shows that RBSO are characterized by the science-based nature of the knowledge being exploited, the close relationship with the parent organisation, and specific firms' internal features. Given the particular characteristics of these firms measuring their impact by traditional indicators, such as employment and turnover, are insufficient. The various empirical studies focus on the one hand on the impact of spin-offs firms on research organizations, in particular on Parent institution and on the other hand on its economic and regional impact It is considered that the RBSOs impact is more clearly expressed through the value they create in knowledge and innovation networks, as agents of knowledge acquisition, transformation and diffusion. However the potential role of RBSOs as an intermediary between academia and industry is much less discussed. The objective of this paper is to address this gap, contributing to understand whether RBSOs are effectively acting as knowledge dissemination mechanisms, through their position in innovation networks. For this purpose, the paper investigates the innovation networks established by RBSOs, at national and European level. In order to address this question, we conduct an analysis of the formal innovation networks established by Portuguese RBSOs in the context of collaborative research, technology and product development (RTD) projects, between 1992 and 2014, drawing on two sets of data: collaborative RTD projects funded by national support programmes and conducted in Portugal (Innovation Agency database) and joint RTD projects conducted in the context European Framework Programmes (CORDIS database). All the projects with spin-off involvement were identified; totalling 453 projects identified which represent 504 participations by RBSOs, (278 participations in Portuguese projects and 226 participations in European projects). The analysis addresses the formal innovation networks formed in the context of these projects, focusing on partner composition. It compares the composition of the national and European knowledge innovation networks (overall and for specific industries) in order to understand: i) whether they differ and along which dimensions; ii) whether it is possible to discern specific patterns of behaviour among RBSOs that suggest the presence of different strategies and roles. The results provide some indications towards the extent and nature of RBSOs role as knowledge conveyors and the forms this role assumes in national and international innovation partnerships.