the present study seeks to determine the effect of explicit instruction of metacognitive strategies on iranian high school students’ reading comprehension ability. it also attempts to investigate the relationship between the learners reading comprehension and metacognitive strategies. furthermore, the study investigates whether iranian efl female high school students are high, medium, or low metacognitive strategy users. to this end, 70 female students who studied in high school were selected. the instruments used to collect the data were a proficiency test, a self-report questionnaire, and a reading comprehension test. data analysis proved no significant relationship between metacognitive strategies and iranian female students’ reading comprehension at high school level. while, it was revealed that there is a significant effect of explicit instruction of metacognitive strategies on students’ reading comprehension. the present study also revealed a significant difference among the level of metacognitive strategy use among high school students and indicated its participants to be low, medium, and high metacognitive strategy users. the findings of this study can be beneficial for language teachers, syllabus designers and language learners.