Critical pedagogical approach entails the application of higher order thinking skills; such an approach can also be justified in more specific terms for second or foreign language pedagogy. That is, critical reading, as a branch of critical approach, is not only of value in itself, but also facilitates language acquisition in a foreign language setting (Wallace, 2003). On the other hand, reading has been the skill most emphasized in traditional FL teaching, and even today it is the mainstay of EFL instruction in many countries. Nowadays, in the field of ESL/EFL, the ultimate goal of teaching reading is reading critically, to be able to evaluate an author's argument and to relate that argument to other texts, and to their own experience. Reading critically assumes having effective strategies which help reading comprehension. The present study investigated the impact of writing summary as a critical reading strategy on reading comprehension ability of Iranian EFL learners. In order to carry on the study, 60 participants at intermediate level of language proficiency were randomly assigned to two groups as the experimental and control group. The participants in the experimental group learned and practiced writing summary, whereas the members of the control group practiced reading texts in the traditional way and both groups answered comprehension questions. The results of the comparison between the means of the two groups through t-test proved that writing summary as a critical reading strategy has a significant effect on improvement of reading comprehension of the experimental group.