This article traces the ways in which notions of diversity inhered in educational policies and practices to mediate the everyday schooling realities of immigrant youth in a Catalonian public secondary school. Diversity, even as it was celebrated and shrouded in liberal appeals to tolerance and cosmopolitanism, was also something requiring management. Diversity discourses produced and marked immigrant youth in disciplining ways, reinscribing narrow notions of difference that ultimately delimited the school's available approaches for addressing diversity.