The present study aimed to investigate the effects of YouTube-assisted listening instruction (YALI) on the listening anxiety of students of German as a foreign language (GFL) and their listening comprehension performance. For this purpose, a total of ninety-six senior undergraduate students were equally divided into three groups using the criterion sampling technique: (a) YouTube-assisted listening instruction (experimental group); (b) traditional listening instruction with auditory materials (control group - 1); and (c) instruction without listening exposure (control group - 2). The instructional approach was underpinned by Richard E. Mayer's Cognitive Theory of Multimedia Learning (CTML). After a ten-week treatment process, results revealed that the students in YALI showed the best GFL listening comprehension performance compared to the control groups. In addition, YALI was observed to reduce students' GFL listening anxiety. Finally, a negative linear correlation between listening anxiety and listening comprehension performance was detected. This meant that students' listening anxiety decreased as their listening comprehension performance increased. To gain a better understanding of the effects of YALI on GFL listening comprehension performance and listening anxiety, relevant implications were discussed.