The widespread prevalence of dynamic tools to assess English language achievement has led to burgeoning research on exploring different aspects of teachers' beliefs toward Dynamic Assessment (DA). In the educational system of Iran, experts and researchers who have undergone second language education may verify that there is very little, if any, attention given to the perceptions held by instructors and teachers regarding Dynamic Assessment (DA). In an attempt to remedy this gap, the current study aimed to investigate the familiarity with DA of Iranian EFL teachers working in two educational settings (e.g., language institutes and universities). The study also set out to explore the teachers' attitudes toward the practicality of DA in the two settings. To address the research questions, a sequential explanatory mixed methods design was employed. The instruments of this study comprised a questionnaire and an Email interview with 12 ELT assessment experts in order to have their interpretations of the research findings. The results of the t-tests showed no significant difference between the two groups of teachers in terms of their familiarity with DA and their attitudes toward the practicality of DA in the two contexts. In addition, content analysis of the Email interview data revealed that the ELT assessment experts' primary arguments for the insignificant difference between the two groups in terms of the two variables related to the fact that DA has remained at the theoretical level, that there is a lack of teacher training in DA and the strict rules of Iran's educational system which prohibit teachers from applying DA principles and procedures in their classes. The implications of the findings for teacher education, materials development as well as for program administrators, EFL teachers, and learners will be discussed.