This paper considers the case of Intercultural Understanding (IU) as a component part of foreign language learning and teaching in the upper stage of primary schools (roughly ages 7-11 years) in the UK. It is set within a specific context of curriculum innovation, namely recent policy changes which have introduced IU as a key part of primary modern foreign languages (PMFLs). The paper begins with setting out the background to this policy and the place of IU within it. It then addresses the following questions: how is IU defined and what is the theoretical rationale for it occupying such a prominent position in the PMFL curriculum? Is there a link between the theoretical justification for IU inclusion and its practice? Is there the danger that the rhetoric surrounding IU promises more than it delivers? The way in which IU is treated in the PMFL curriculum in the UK is then contrasted with a range of other IU schemes and taxonomies. Finally, it raises a number of pertinent issues with respect to IU and assesses its potential role in future developments in PMFLs.