Materials preparation is an important stage in EAP curriculum. There is a pressing need to shed more light on EAP teachers’ materials preparation abilities, especially in contexts like Iran, where EAP courses are taught by two groups of teachers with different specializations; that is language teachers and content teachers. Therefore, this nationwide study explored the similarities and differences between the cognitions and practices of the two groups of EAP teachers concerning their materials preparation abilities, at medical sciences universities across Iran. In order to answer the research questions, a triangulation of methods and sources, and a wide range of instruments, including questionnaire, semi-structured interviews, observations and field notes were utilized. A representative sample of 128 language teachers and 190 content teachers from all medical sciences universities participated in the study. The results of the questionnaire indicated that there were no differences between language teachers and content teachers; however, the interviews and the observations revealed substantial differences between the two groups. The findings present some implications for the EAP community and a need to renew the current materials.
