The use of dynamic assessment (DA), grounded in Vygotskian Sociocultural theory, in classrooms is believed to have the potential to provide a situation for creating a group of learners' Zone of Proximal Development (ZPD) (Poehener, 2009). The present study explored the implementation of DA in English as Foreign Language (EFL) classrooms on groups of learners at different proficiency levels in the context of listening comprehension. 146 Iranian EFL learners at three proficiency levels were selected for this study (experimental groups=71 and control groups=75). A multi-assessment procedure in the format of dynamic and non-dynamic pretest-enrichment phase-dynamic and non-dynamic posttest was conducted.During the nine-week group dynamic assessment procedures, mediational strategies were only given to the experimental groups. The quantitative data analysis revealed that through mediated interactions within the group's ZPD, group dynamic assessment is able to determine the learners' developed abilities in listening comprehension while at the same time support the development of individual learners in this skill. Moreover, it was found that the level of proficiency of the learners did not have a significant effect on learners' gains from group dynamic assessment procedures. These findings can have implications for all classroom teachers that the use of DA in classroom setting cannot only be beneficial to them but also be considered as a strategic learning and assessment method that can meet both the learners' and teacher's needs.