Argumentative writing is the most important genre which undergraduates need to learn
in order to meet their academic requirements. Regardless of the different disciplines in the
academic context, the development of a well-formed argumentative essay is regarded as an
important skill, particularly in the arts, humanities, and social sciences. Nevertheless, many
studies in different native and non-native contexts have indicated many problems that
undergraduates have experienced when developing an argumentative essay. To shed more light
on how undergraduate students deal with argumentation in the Iranian EFL academic writing
context, the present study was conducted. For this purpose, a total of 66 argumentative essays
written by undergraduate students was analyzed. In addition, a group of 30 undergraduate
students majoring in English literature and 6 writing instructors were interviewed. The findings of
the analysis of the students’ texts showed that the students had difficulties in different aspects of
argumentative essay development. In particular, the concept of argumentation was poorly
conceived and tackled by the learners. Teachers also had a tacit knowledge of argumentations
lacking a coherent approach for teaching the argumentative essay. In sum, the study proposes that
the failure to develop an argumentative essay by the Iranian undergraduates entails several
academic, cultural, and pedagogical grounds. Implications for improving argumentative writing
development in EAP contexts are also provided.