The curriculum for the Environmental Studies subject which is taught in the Republic of Slovenia in the first three grades of primary schools is based on the constructivist and humanistic theory of learning and teaching. For teachers, textbook sets are a crucial aid in implementing the learning process. For the aforementioned subject, there are many sets and several factors that affect their choices. In this research study, we interrogated which textbook sets teachers use and how these help them in implementing the constructivist teaching for the Environmental Studies subject. The research was conducted on a representative sample of third-grade teachers. We found that teachers mainly use three textbook sets from various publishers and that there is only one in which the proposed and anticipated pupils’ activities, methods and forms of work assume a more active role for the pupils during the learning process

Keywords: Primary school, Environmental Studies subject, third year teachers, textbooks sets