In this research, teachers' orientations in curriculum theories were identified via an assessment tool which was grounded by Marsh and Willis (2003) where curriculum theorists were classified. "The Inventory of Orientations in Curriculum Theories" was developed to identify the teachers' orientations in curriculum theories in this research. The item pool for the inventory was obtained through a qualitative clustering analysis applied on the studies in the related literature. Later, Exploratory Factor Analysis and Confirmatory Factor Analysis were applied separately on each scale of the inventory. As the result of this process, "the Inventory of Orientations in Curriculum Theories" was developed which consisted of "the Scale of Orientations in Prescriptive Curriculum Theories", "the Scale of Orientations in Descriptive Curriculum Theories" and "the Scale of Orientations in Critical-Exploratory Curriculum Theories". In this context, a new culture-specific measurement tool has been developed that aims to determine the interaction between scientists, specialists and teachers in the field, in other words, theorists and practitioners. The IOCT inventory consists of three scales: OSPCT, OSDCT and OSCECT. OSPCT consists of 27 items, OSDCT consists of 18 items and OSCECT consists of 19 items. The highest score that can be obtained from OSPCT is 135 and the lowest 27; The highest score that can be obtained from OSDCT is 90 and the lowest is 18; the highest score that can be obtained from OSCECT is 95 and the lowest is 19. Thus, it can be determined to what extent a teacher has a prescriptive, descriptive or critical-explanatory curriculum theory orientation.