Regarding the importance of ELT textbooks as one of the most important resources in any language teaching context and their influence on students’ world perspective, and the interdependence of language and culture, the main thrust of this study is to describe and analyze two series of ELT materials developed for non-native speakers of English in terms of their hidden ideologies. One is the new series of Iranian ELT textbooks for high school, namely Prospect 1 , Prospect 2, and Prospect 3, and the other is an international ELT textbook, namely American English Files series, the starter volume. This research employed Fairclough’s (2003) analytical framework of Critical Discourse Analysis (CDA) to explore and analyze cultural themes in the series. This research is a qualitative and quantitative one relying mostly on the way of representing source, target, and international target culture in the textbooks to explore the ideologies behind them. The qualitative findings of this study revealed that the two series are replete with cultural ideologies each of which represents different ideologies. On the other hand, the quantitative analysis reveals that the domestic textbooks were mostly source culture oriented; whereas the international textbook mostly represented the international target culture.
