The objective of the current paper was set to examine the effect of second language reading strategy instruction on young Iranian English as a Foreign Language (EFL) learners' reading comprehension. To accomplish this objective, a sample of 48 Iranian EFL learners, aged 11-13, were selected and randomly assigned to an experimental group (N = 25) and a control group (N = 23). Employing a quasi-experimental design, the study employed an experimental group that underwent a 12-week reading strategy instruction and a control group that were taught with regular method with no strategy instruction but they were measured in terms of reading comprehension before and after the strategy instruction. The reading component of Cambridge Preliminary English Test (CPET) was given to assess the reading comprehension performance of the participants as pre-test and post-test of the study. The collected data were analyzed through conducting paired samples t-test and one-way ANCOVA. The findings of the study revealed that the learners in the experimental group outperformed those of control group with regard to reading comprehension after receiving the strategy instruction intervention. Pedagogical implications on reading strategy instruction were also discussed.