•The study firstly focuses on mapping the lagging-behind European regions.•Co-patenting is used to define networking capacity of local organisations.•Panel modelling is implemented based on RegPat and Eurostat databases.•Results suggest wider interregional networks perform better than local networks.•Collaborations with knowledge-intensive regions are specifically relevant. In rapidly changing regional economies, less innovative European regions (henceforth referred to as lagging-behind regions) must actively work to reduce the gap between them and knowledge-intensive regions. Recent literature has stressed that the lack of efficient institutional settings reduces the opportunities of local knowledge spillover and increases the need for local organisations to exploit collaborative networks to better support their innovation performance. In this light, since increasing attention has recently been directed at the role of inter-regional collaborations, we have measured the capacity of local innovative organisations embedded in lagging-behind European regions to develop internal and external regional inventors’ networks by exploring their collaborative patenting processes. Then, a seven-year panel dataset (2002–2008) was organised using patents data at a regional level to validate the research hypothesis that collaborations, and specifically with highly innovative (knowledge-intensive) regions, positively affect the innovation performances of lagging-behind regions. Finally, the implications of EU policies for supporting lagging-behind regions are discussed.