The present study investigated the influence of concept mapping as a post-reading strategy on EFL learners' critical thinking ability. The study utilized a pretest-posttest control and experimental group design. To do so, thirty six EFL learners at upper intermediate and advanced levels were randomly assigned to experimental (n=18) and control (n=18) groups. The results of pretest indicated that the participants of the two groups were homogenous with regard to their proficiency level and critical thinking ability. The experimental group was instructed to construct concept maps after reading each text and formulated the required post-reading activities on the basis of the constructed maps. Critical thinking skill was assessed via the "Watson-Glaser Critical Thinking Appraisal" (CTA). The results of posttest indicated that concept mapping has a positive and significant influence on learners' critical thinking ability. The discussion and conclusions of the research are further presented with reference to the finding.