The current study was intended to investigate the impact of Dynamic Assessment (DA) on promoting reading comprehension ability of Iranian male and female EFL learners, focusing on Guthke's Lerntest approach. In this study, the researcher used DA which unifies instruction with assessment to provide learners with mediation to promote their hidden potential during assessment. In this action research project, Guthke's Lerntest approach was used to develop the reading comprehension skill classes that integrated mediation with assessment to support 60 Iranian EFL learners' reading skill. The Guthke's lerntest approach and the mediation design are presented in detail in this article. The participants' reading scores are presented to show the effect of Guthke's Lerntest approach on promoting Iranian EFL learners' reading performance. In addition, the participants' pre and post-test scores were compared to determine whether the participants revealed significant progress after receiving Guthke's Lerntest approach in reading comprehension setting. The findings showed that participants of experimental group significantly outperformed the one in the static way. In conclusion, the results of the study revealed that employing the Guthke's Lerntest approach can offer a new condition to enhance the EFL learners' reading comprehension ability and that doing research in this field can be beneficial for EFL learners, English instructors and other researchers in other fields.
