The study focused on the process of implementation of International Baccalaureate (IB) Middle Years Programme (MYP). The purpose of the study was to get an in-depth understanding of the factors which influenced the initiators to implement the IB MYP, and the challenges they faced in implementing the programme in the Pakistani context, through the principal and the IB coordinator's experiences and perceptions. The study was done through the qualitative case study research approach. The duration of the study was six weeks. The targeted population consisted of two participants (the Principal and the IB coordinator). Data was collected through semi-structured interview, observation, unstructured conversations with the teachers, document analysis and reflection. My analysis started from the first day of fieldwork in the form of reflection and analytical memos. The major limitation of the study was lack of research on IB especially IB MYP, thus, the findings have been compared mainly by the literature based on educational reform and school improvement. The study found that the process of implementation included the following elements; planning, creating awareness, moving through phases, and putting decisions and ideas into practice. The findings indicated that the principal's personal interest in the broad philosophy of IB MYP guided and influenced him to implement the programme in the Pakistani context. The main aim of implementing the IB MYP was to bring quality education in the context of Pakistan. The school faced several challenges such as; pedagogical challenges, challenges in curriculum and management practices, lack of community awareness and language policy in implementing the programme in the Pakistani context. During the process of implementation, the school resolved some of the challenges successfully. First of all, principal's leadership facilitated the implementation process. Besides this, the school followed different steps such as; arranged workshops and training programmes to empower the teachers. Moreover, school's climate of collaboration, team work, fear-free relationship among the administration, teachers and the students, and the supportive monitoring and evaluation process influenced the implementation of IB MYP in the school.