The article highlights the concept of foreign language teacher agency which can manifest itself in the teachers` decision to introduce changes to the coursebooks they use. The most significant characteristics of the teacher agentic position in this area are clear motives and goals for change, a detailed analysis of the context and of the tools (including coursebooks) that are necessary for positive learner outcomes, an autonomous decision to choose and use the teaching materials that can facilitate effective learning. All these require teacher self-regulation and reflection. The article aims to find out if foreign language teachers are inclined to change coursebooks and why some teachers reject any changes, what factors affect their decision, and what kind of changes are common. The present research is based on the teachers` answers to a questionnaire that was offered to 182 foreign language school teachers from 2015 up to the beginning of 2020. All the respondents were divided into two groups: professionally active teachers in the community (32 teachers) and those who do not actively participate in the regional professional activities (150 teachers). The results of the study prove that the teacher`s readiness and ability to introduce coursebook changes are a significant indicator of the overall teacher agency. Though the study has a few limitations, its outcomes can be beneficial for both pre-service and in-service teacher education in terms of coursebook evaluation and material choice/development skills.

teacher agency, indicators of teacher agency, coursebook changes