Purpose: The purpose of the present study was twofold. First, we aimed to adapt the English-speaking Anxiety Scale. Second, we intended to investigate the mediating role of English learning motivation and self-confidence on the relationship between English-speaking anxiety and English self-efficacy through a serial mediation analysis. Design/methodology/approach: The first phase included the adaptation of the English-speaking Anxiety Scale into tertiary level based on data collected from 178 students. The second phase tested the theoretical serial mediation model based on data collected from 526 students. Confirmatory factor analysis was performed to serve for the first purpose of the study whereas PROCESS macro (Model 6) was run to test the serial multiple mediation roles of English learning motivation and self-confidence. Findings: The results of CFA showed that the fit indices of the adapted version of the scale were acceptable. Besides, it was found out that English learning motivation and self-confidence played multiple mediating roles in the relationship between English self-efficacy and English-speaking anxiety. Originality/value: This research offers a valid and reliable scale to determine the English-speaking anxiety of tertiary level students. Also, it sheds light how English learning motivation and self-confidence mediates the relationship between English-speaking anxiety and English self-efficacy for the first time. Pedagogical implications of the study for future research were presented at the end of the study.