The literature on foreign language reading instruction has witnessed a significant bulk of research reporting the effectiveness of strategy instruction in improving reading outcomes. However, few studies have investigated the effects of reading strategy instruction on reading affective variables among young English as a Foreign Language (EFL) learners. The aim of this study was to investigate the effect of teaching second language (L2) reading strategies on young Iranian EFL learners’ reading self-efficacy and reading attitudes. To this end, a sample of 48 Iranian EFL learners, aged 11-13, was recruited through convenience sampling and randomly assigned to an experimental group (N = 25) and a control group (N = 23). Using a quasi-experimental design, the researchers employed an experimental group that received a 12-week reading strategy instruction and a control group that were taught with the regular method without any strategy instruction. The Reading Self-Efficacy Questionnaire (RSEQ) and Reading Attitude Questionnaire (RAQ) were administered to measure the reading self-efficacy and reading attitudes of the participants as pre-test and post-test of the study. The strategy instruction intervention for the present study was based on Cognitive Academic Language Learning Approach (CALLA). The findings of the study indicated that the learners in the experimental group significantly outperformed those of the control group in terms of L2 reading self-efficacy. However, it was revealed that there was no significant difference between the reading attitudes of the two groups at the end of the semester. Overall, it may be concluded that EFL practitioners can incorporate teaching of reading strategies into their classrooms in order to help learners to gain both confidence and competence to address reading tasks more effectively.