Learning a new language depends on so many factors such as learners, teachers, environment, purpose of learning or teaching, and more importantly textbooks. Textbooks are a key component in most language programs. For most teachers, textbooks provide the foundation for the content of lessons, the balance of the skills taught, as well as the kinds of language practice the students engage in during class activities. This paper aims to evaluate the authenticity of the Iranian English textbooks at high school level. It is based on Dougills’ textbook evaluation checklist. According to the feedback received from the teachers’ and the students’ responses, the home-made textbooks lack the authenticity of natural English in terms of content and presentation. They are short in the variety and attractiveness in the passages. The materials are not generally presented from the easy to hard order and they are mainly void of cultural and communicative points.