This research is a qualitative case study aiming at analyzing the effects of accreditation on school system elements. Accordingly, interviews were conducted with administrators and teachers at an IB-PYP accredited school. There are questions directed towards understanding the impacts of the accreditation on the elements of open system in the semi-structured interview form used for the data collection tool in the interviews. Thematic analysis was utilized as the data analysis method. Inputs, process, outputs, feedback and environment elements of open system were used as the data analysis framework. According to the study results, the administrators and teachers think that accreditation has positive effects on the school system. However, the school community's attitude, the staff's professional competency, communication and teamwork skills have a decisive role in the formation of these positive effects and successful implementation of the program. Moreover, it could be stated that schools devise strategies to manage the dilemma they encounter among the national system, exam pressure and the program's objectives, and learning outcomes.