Abstract: The present research was primarily intended to examine how ideology affects the lexical choice for transmitting the intention of the speaker or writer and to convey their intended meaning to the addressees and then to explore its implications for foreign language teaching. The study compared two educational TV series (Extra English and Green Valley), investigating the lexical choice in each, and analyzing the possible hidden messages.The selection of the lexical items has been on the basis of the comparison between the Secular ideology and the Islamic ideology, utilizing Critical Discourse Analysis and Fairclough's values of the formal features framework for the analysis of the lexical features. Then the selected lexical features were related to the concepts of hidden and null curriculums. It is concluded that in each TV series the lexical choice is an indication of and governed by the underlying ideology of the series.