The purpose of this study is to explore language teachers' perspectives on Iranian third grade senior high school EFL textbook, which is prescribed by the Ministry of Education. In data collection and analysis, the researchers used theoretical sampling and the coding schemes presented in grounded theory. Final analysis yielded "Negative Evaluation of English Book 3" as the core category, and eight subcategories including "Dullness of pictures", "Disregarding Learners' Interest", "Grammar Overload", "Inadequate Explanations", "Inefficient Presentation of Pronunciation", "Contrived Dialogues" and "Decontextualized Vocabulary", and "Ignoring Language skills", which capture the teachers' perspectives on Iranian third grade senior high school EFL textbook. The results have clear implications for curriculum development, syllabus design.