Contemporary industrialization was a process that raised the Basque society from the profound crisis in which it was immersed at the start of the 19th century, and is the most relevant event of its history. Bilbao was the nucleus of this transformation, and at the start of the 20th century it was already the new focus of industrial and demographic development of the region and of the north of Spain as a whole. The development of craft sectors into small companies and the integration of new production methods in an advanced capitalist system are the two steps in the modernizing process analyzed in this research project. The publication also studies how the industrialization process took place, and what implications it had on the demographic, social and spatial structures of the city.