The purpose of this study was to examine the impact of using content schema activation strategy; ' Know", "Want to know", and "Learned" (KWL) through using some Quranic stories on improving reading comprehension skills of EFL secondary stage Al-Azhar students. The study adopted the quasi-experimental design employing two groups; experimental and control. The KWL strategy was used in teaching the experimental group in the first term of the academic year (2017-2018). A reading comprehension test was designed and validated to be used as a pre-posttest. The data of the study were analyzed statistically. Also, t. test for paired and independent groups was used to measure the statistical differences between the mean scores of the experimental group and the control group.  The study indicated that there was a statistically significant difference between the mean scores of students of experimental group and control group on the post administration of reading comprehension test in favor of the experimental group. The results showed that the use of KWL strategy had a significant impact on improving students' reading comprehension skills. In conclusion, the study recommended implementing other content schema activation strategies for improving Al-Azhar students' reading comprehension skills. It was also suggested that further research should be conducted related to using KWL strategy for developing other language skills such as listening and writing. Key words: Content schema activation, Reading comprehension skills, Quranic Stories, Secondary stage Al-Azhar students.