This article aims to contribute to the reflection on the diversity of collective action processes in urban contexts, in this case located in realities, processes, dynamics, and socio-territorial experiences of the city of Medellín. It is expected to contribute to the understanding and up¬dated reflection on contemporary urban social movements, their practices and struggles in the production of more humane, dignified and inclusive cities, which for the case studied could unveil alternative planning and territorial construction proposals with a plausible articulation to institutionalized proposals. The reader will find a synthesis of the research that supports the document, followed by an approach to the relationship between urban policy and collec¬tive action in the city of Medellín, as well as to social movements and the analyzed actions of territory defense. Finally, some conclusions on the subject are presented.