Seeking to understand how cultural events intervene in contemporary social dynamic, this chapter focusses on processes of marginalisation at work in two urban festivals: the Mexefest (Lisbon) and Virada Cultural (São Paulo). Cultural festivals are situated at the intersection of gentrification processes, urban renewal projects and strategies of social control. Using a qualitative approach based on Actor-Network Theory, the research combines semi-structured and unstructured interviews, direct observation and documentary analysis. In this way, it attends to (1) formal events of the programme announced in both festivals and (2) pre-production meetings (media conferences, brand marketing campaigns and related forms of promotion). As a device of social control that mediates urban conflicts in their respective cities, both festivals represent more than a cultural experience. They implement cultural policies, enforce security and promote multiculturalist discourses. As such, they both facilitate and control the occupation of urban centres by marginalised social groups.