This paper explores the issue of ‘open mindedness’ in the IB Learner Profile. The study focused on the MYP years in UK IB schools. It adopted a mixed methods approach. A survey completed by over 574 11-16 year olds sought to assess young people's responses in relation to a number of different aspects of 'open-mindedness'. Qualitative data was collected from four case study schools, both state sector and independent. Interviews were conducted with school leaders, teachers and students and focused on the processes associated with developing ‘open-mindedness’ amongst young people. The paper identifies a range of different ways in which teachers seek to operationalise the concept of open-mindedness. It argues that teachers develop ‘open-mindedness’ as both a learning outcome and a pedagogical approach. However, the paper will highlight some of the challenges teachers face when seeking to promote open-mindedness in their pedagogical practice, not least the tensions that can flow from different cultural expectations about what is ‘acceptable’ in the classroom.