This study aimed to investigate the relationship between foreign language causal attributions, metacognitive self-regulation and speaking performance of Iranian EFL learners. To this end, 202 intermediate EFL students, studying English at private language teaching institutes in three provinces of Hamedan, Golestan, and Khuzestan were selected based on the convenience sampling procedure. To collect data, Causal Dimension Scale II (CDS II) (McAuley, Duncan, & Russell, 1992) and Motivated Strategies for Learning Questionnaire (MSLQ) (Pintrich, Smith, Garcia & McKeachie, 1991) were utilized. Moreover, the interview section of IELTS Exam was also used to measure speaking ability of the learners. The results of the study showed that there was significant positive correlation between the participants’ L2 speaking ability and the locus of causality and the internal control dimensions of attribution theory. But, there was significant negative correlation between L2 speaking ability and the external control and the stability dimensions. There was also positive significant correlation between L2 speaking ability and metacognitive self-regulation. Moreover, it was found out that successful and unsuccessful EFL learners attributed their success and failures in L2 speaking performance mainly to internal factors. It was also found that among the independent variables of the study, meta-cognitive self-regulation was the stronger predictor of the participants' L2 speaking performance. The findings of this study are hoped to suggest a number of implications for EFL teachers and learners, syllabus designers, and parents.
