Systemic perspectives of innovation integrate complex interrelations among enterprise, science and technology, and governance spheres. Innovation networks are crucial within innovation systems and refer to the linkages of a variety of actors with the purpose of innovation. In this article, the determinants of innovation networks are analyzed using a qualitative original database of online information about 623 organizations in Portugal. A binary econometric regression for all types of entities is estimated. The model underlines that actors using external technologies and promoting knowledge are more likely to innovate. In parallel, actors that are involved in managing and supporting entrepreneurship have a smaller probability to do it. Advanced firms and universities are the actors more willing to dynamically innovate. Specific models for firms and universities create a direct comparison between the determinants in both collectives. While promoting knowledge and specific orientation towards innovation is essential for firms it is not relevant for universities. Managing knowledge is the crucial catalyst for the innovation practices in universities. External technological linkages are essential for both types of actors in the creation of innovation networks. The article concludes with policy implications regarding the support of cooperation activities to instigate innovation.