The theoretical discourse on intercultural diversity is still far removed from practice. One reason for this gap is the lack of properly trained teachers (both present and future). To implement the intercultural approach, it is essential to know the discourse of the agents who will apply it. The purpose of this study is twofold: (1) to determine the dominant approach to intercultural discourse through a case study with subcases of future teachers, and (2) to determine what barriers they identify regarding the implementation of intercultural practices in schools. To this effect, 30 focus groups consisting of first-year students (302 in total) enrolled in the BA in Early Childhood and Elementary Education at the Faculty of Education at the University of Alcalá (academic year 2011-2012) were interviewed. The results indicate that (a) perhaps due to a lack of experience in cultural diversity, the primary discourse perspective is compensatory and assimilationist; and (b) there are four main barriers between theory and practice: lack of knowledge, personal values inconsistent with interculturality, stereotyped ideas, and the lack of a transversal vision in the curriculum.