This paper presents an overview of co-patenting trends at the national and regional level in three technology fields (biotechnology, telecommunications and renewable energy), across regions in the OECD and emerging economies, from the late 1970s to the late 2000s. After a general introduction on regional patenting activities, inter-regional co-inventorship networks in the three selected technologies are built and analysed. Different behaviors and relative network positioning emerge, in terms of top patenting regions both across technological fields and over time. Co-patenting networks increase their density over time and they show preferential attachment properties, namely regions with a central position in an early phase of development of the network tend to maintain their positioning in the future. However, there are also windows of opportunity for new central nodes to emerge in the network. Evidence shows that the structure of the network evolves differently depending on technological field and that the role of spatial proximity and capability proximity is mixed in influencing co-inventorship patterns. Co-patenting networks include star players that establish connections regardless of the proximity of partners; but also several wellperforming actors that benefit from proximity or relative proximity of agents.