The present study aimed to investigate the effect of the metacognitive intervention on the listening performance and metacognitive awareness of a group of upper-intermediate Iranian EFL learners who were all in possession of low working memory capacity (WMC). 136 male EFL learners aged between 15 and 25 years were given Oxford Placement Tests (OPT). Of the 136 learners, 94 learners were identified as upper-intermediate learners who were eligible to participate in the study. They were all learning English as a foreign language (EFL) at the English Language Institute (ELI) in Iran. They were further given the Visual Digit Span Test (DST). Based on their scores and the median, they were assigned to experimental (N=30), and control (N=30) groups. The experimental group (low WMC learners) received the metacognitive intervention through a pedagogical cycle for 10 sessions while the control group (high WMC learners) followed their traditional approach without receiving a pedagogical cycle. The participants in both groups were asked to complete the Metacognitive Awareness Listening Questionnaire (MALQ) and to take the International English Language Testing System (IELTS) listening tests before and after the intervention. The results suggested that the experimental group had a higher gain with a moderate effect size in terms of listening performance than the control group. In addition, the experimental group reported the significantly higher use of directed attention, mental translation and person knowledge. The findings suggest that there is room for metacognition in material development and signal the need to adapt teaching methods to low working memory capacity learners.
