abstract Literature on innovation networks reveals little of to what extent different types of knowledge are exchanged and combined by collaborating firms to foster innovation. Based on field research in the aerospace industrial cluster of Rome, this study investigates the exchange of technological, market and managerial knowledge. Using social network analysis, the paper shows that the three types of knowledge are unevenly distributed and exchanged, thus revealing that the process of exchange is knowledge-specific. Further, it is found that in most collaborative relationships, partners exchange technological knowledge together with market and managerial knowledge, emphasizing the complex nature of the innovation process which requires access to and recombination of diverse knowledge. This phenomenon concerns not only large companies, but also small-to-medium enterprises. The reconsideration of the relative salience of the three types of knowledge has remarkable managerial and theoretical implications, which are developed in terms of propositions offered for further research.