This study investigates the responses of teachers in an Arabic school in west London to the introduction of a new school-mandated curriculum: the International Baccalaureate (IB). The study focuses on seven teachers in the major subject areas of English, science, maths, Arabic language, Islamic studies, ICT and French language. As a result, this study found it necessary to employ qualitative research methodology using in-depth interviews to gain an understanding of teachers within the context of their practice. This research provides a basis for analysing how teachers experience and understand change. The research revealed a phenomenological perspective of teachers' actions. Analysis of the data is organised into four main categories: teaching career for participants; teachers' views about IB; introducing the IB to the school and the future of the IB in the school. The findings suggest that change does not result because it is mandated by central management, but certain factors—such as school-based support, perception of autonomy, collaboration, participation in curriculum development, professional development, academic preparation and experience—influence teachers' response to change. When these factors are evident, teachers respond favourably to change. Implications of these conclusions are discussed as are further questions and opportunities for further research.