The alleged North-Western Iberian urban corridor, mainly covering Northern Portugal and Galicia, is examined. The international boundary between Portugal and Spain is assumed to have a role in the analysis of such a corridor. The theoretical section reviews the literature on urban systems and corridors and shows how they are commonly conceived under a nation-state framework. Some of the international literature on urban corridors has been criticised given that it is not based on actual inter-urban links. The results are based on the analysis of the literature about the North-Western Iberian urban corridor developed in Portugal and in Galicia. The intention is to grasp to what extent the corridor has emerged as an academic spatial category in both countries. The paper concludes by discussing the results and by providing some final remarks regarding inter-urban and inter-regional cross-border governance and the relevance of other scales rather than individual cities for the development of smart city agendas.