This article aims to analyse and compare the patent collaboration networks of Spain and Sweden during the Second Industrial Revolution, a key period for technological and industrial development in several economies and the distinct development paths taken by these two countries. The data used are from two new historical patent datasets for Spain and Sweden for the period 1878–1914. To study the structure of collaboration networks in both countries, we applied social network analysis methods and focused on two specific key network properties: connectivity and openness to external nodes. The results demonstrate that collaboration networks were better connected and more open to foreign influence in Sweden than in Spain. This research opens new paths for further multidisciplinary studies both on the evolution of industrial economies and on innovation networks dynamics.