The present study attempts to investigate Persian cultural conceptualizations (hereinafter CCs in the text) placed in the reading passages of the English textbooks published by one of the most prominent publishers in Iran. Employing the principles of critical literacy, together with the investigative framework of Cultural Linguistics, content analysis revealed that despite portraying some universally acknowledged conceptualizations in the readings, not all of them necessarily depicted Persian CCs. Furthermore, the study found that the processing questions and activities were confined to low order comprehension questions and language exercises, with few opportunities for the audience of the textbooks to get involved thoroughly with the conceptualizations used in the readings or challenge ways of thinking inserted in the passage in spite of the allegedly critical approach shaping the series. Accompanied by semi-structured interviews, the study concludes by offering practical pedagogical implications for materials developers and textbook designers. To further elucidate the purpose of the study, a tentative reading task concerning a Persian CC is developed and offered in the appendix.