This study aimed at investigating the effect of E-mind mapping on Prep School Students' Metacognitive Reading Skills. To achieve the study aims, the researcher adopted the quasi-experimental approach on participants of (50) students at Abdel Wahab Elgohary Prep School.  The participants were divided into two equivalent groups. Both groups were pretested to assure that they were equivalent.  The experimental group was taught using E-mind mapping while the control one was taught by the regular method in the first term of the scholastic year 2019-2020. The experiment lasted for seven weeks in which the researcher implemented the study instruments to investigate the effect of E-mind mapping. The results were statistically analyzed by SPSS to be compared with the post-test results. The researcher used three instruments to collect data: 1) questionnaire to determine the most important Metacognitive Reading Skills, 2) a pre/post Metacognitive Reading Skills test and 3) a metacognitive reading skills rubric to determine the students' metacognitive reading skills performance.   The results revealed that there were statistically significant differences at (α = 0.05) between the mean scores of the control group and those of the experimental one on the metacognitive reading skills posttest in favor of the experimental group. This positive result was attributed to the effect of using the E-mind mapping.  According to the findings, the researcher recommends that the English Language teachers need to activate E-mind mapping approach throughout reading in order to develop the students' Metacognitive Reading Skills.