This study sought to examine the type and frequency of tasks in the Iranian high school English course books (Prospect 1, 2, 3 & English Book 1, 2, 3). The corpus was analyzed based on Nunan’s (1999) framework composed of five main task types, namely cognitive, interpersonal, linguistics, affective, and creative. To this end, the whole content of the aforementioned course books went through content analysis separately and accordingly descriptive and inferential results were reported regarding the frequency of each task type. The results showed that the linguistic tasks were the most recurrent type, whereas some task types (e.g., affective and creative) were totally absent. Furthermore, based on the results of Chi Square test, a significant difference was observed in the frequency of task types. While, according to communicative approach, communicative competence necessitates the inclusion of grammatical, discourse, sociolinguistic, and strategic competencies, the findings of the current study revealed that linguistic competence was overemphasized in these course books. This fact may lead to learners who are competent in producing linguistically appropriate utterances, which may at the same time be inappropriate with regard to context. The findings can have significant implications for EFL teachers and materials developers in making them conscious of the fact that the application of different types of tasks in textbooks is an important standard leading to more competent language users, especially in an EFL context like Iran. تفاصيل المقالة