The article analyzes the mediation of communication in social movements, as a response to the necessity of an approach to the issue that overcomes instrumentalist perspectives and certain under theorizations on the understanding of the topic. The article aims to identify the main dimensions of social movements that are mediated by the communicative dimension, to describe how this communicative mediation takes place on each previously identified dimension and to analyze the main tensions and complexities of this communicative mediation. Based on a multiple case study of three Latin American social movements and a qualitative perspective of discourse analysis, the article identifies three dimensions of the communicative mediation. In the political-organizational dimension, the communicative mediation is associated with the articulation dynamics and the configuration of organizational forms. In the symbolic-emotional dimension, the mediation is linked to visibility, the emergence of shared senses and the emotional mobilization. In the economic-productive dimension, the mediation of communication is associated with the building of a new sense of collectiveness in the productive process. Based on these main findings, the article concludes that the mediation of communication in social movements have to be understood in a multidimensional and complex way, by avoiding instrumentalist or communicationist perspectives, and proposing the need of understanding this mediation from the articulation between social change and communicative change.