This paper investigates the factor content of international trade of the Spanish regions with the EU-15, using the available regional Input-Output Tables around 1995. The results indicate that Spanish regions exhibit a revealed comparative advantage in line with the predictions of the factor proportions theory. All the regions but Asturias, Balearic Islands, Canary Islands, Catalonia, Madrid y Vasc Country are net exporters of land. There is a mix of regions that are net exporters of physical capital according to their level of development: Aragón, Canary Islands, Catalonia, Extremadura, Madrid and Galicia. Finally, only three regions, Aragon, Navarra and Vasc Country, are net exporters of human capital.