This multi-case study investigated how teaching in an International Baccalaureate (IB) Middle Years Programme (MYP) Individuals and Societies (I & S) classroom influenced teachers' global citizenship (GC) perceptions and pedagogy. Results demonstrate teachers were informed by their personal experiences and district expectations, utilizing a cosmopolitan global citizenship education (GCE) that aligned with the IB MYP philosophy. A disconnect sometimes existed as teachers' rationales for global citizenship recognized the need for multiple perspectives and a critical view, but a reactive or proactive approach influenced instruction. This research effort furthers the discussion on the role an international education framework can have on a teacher's pedagogy, where global citizenship education is situated in the curriculum, and what influences a teacher's thinking and pedagogy. This can be helpful to us in understanding the role curriculum context can have in shaping a teacher's ideas about global citizenship and how they enact those ideas.