The purpose of this study was to determine the contribution of academic vocabulary knowledge and academic listening self-concept to the academic listening comprehension of Iranian Engineering students. The participants of this study were 147 undergraduate students at the Iran University of Science and Technology. A revised version of the academic self-concept questionnaire developed by Liu and Wang (2005), an academic vocabulary test by Schmitt, Schmitt, and Clapham (2001), and a sample of IELTS academic listening test were the instruments of this study. The results of the data analysis revealed that academic vocabulary knowledge and academic self-concept both contributed to the learners’ academic listening comprehension. The results also showed that the contribution of academic vocabulary knowledge to academic listening comprehension was higher than that of academic listening self-concept, indicating that the academic vocabulary knowledge was the significant contributor to academic listening comprehension. This study recommended that EGAP instructors make students aware of the importance of academic listening and help them improve their academic self-concept and vocabulary knowledge. Manuscript profile