This case study investigated the perceptions of the main stakeholders on an institutional classroom observation system in the English language preparatory program of a foundation university in Ankara. In this regard, it explored how the stakeholders perceive the relationship between the institutional classroom observation system and English as a foreign language teachers’ professional development in terms of teaching quality and teacher reflectivity. To this end, 44 EFL instructors, eight classroom observers, and three administrators took part in the study. The data were derived through a questionnaire with open-ended questions, semi-structured interviews, and the document regarding the system was utilized as another data source. The results of the content analysis revealed that each stakeholder group has their own perception on the observation system, and its relation to teaching quality and teacher reflectivity.