R&D Networks comprise different actors with various goals and motivations. Thus, such networks are filled with tensions that emerge from simultaneously existing, competing or contradictory organizing elements and demands. In this study, we examine the knowledge search and integration behaviour of firms participating in R&D networks in the Dutch aerospace sector. We find evidence of a multitude of tensions that have implications for knowledge processes of firms and within R&D networks. These tensions are grouped into dialectical and paradoxical tensions. In particular, paradoxical tensions require simultaneous attention to the different organizing elements, while dialectical tensions create either/or situations that need to be carefully mana...