Resumen Este artículo analiza la formación de una nueva clase obrera en los polos de desarrollo de Patagonia y Amazonia durante y Analizamos cómo se construyó cada clase obrera y qué formas de lucha y organización desarrolló. Palabras clave: polo de desarrollo; clase obrera; Patagonia; Amazonia. Abstract This article analyzes the formation of a new working class in the development poles that were established in Patagonia and Amazonia during the s and s. The growth of industry required the influx of workers to these areas, but this does not imply that there were no workers there initially. However, the scale of the transformation that took place led to the development of what can be called a new class. This class included migrants from various areas who had few traditions and experiences in common and a history conditioned by industrialization dependent on state subsidies. We analyze how each working class grew and the forms of struggle and organization they developed.