The present study dealt with exploring to what extent asynchronous virtual learning environment (ASVLE) and synchronous virtual learning environment (SVLE) enhance students' metacognitive awareness in L3 German learning process. During a five-week intervention, the students of the experimental group were taught L3 German synchronously through the BigBlueButton web conferencing system. In contrast, course notes, video-recordings were shared on Moodle Learning Management System (MLMS) asynchronously with those of the control group. The study was conducted on 72 undergraduates and assessed based on the pre-and post-tests of the Metacognitive Awareness Inventory (MAI) and semi-structured interviews. The findings indicated that SVLE improved the MAI scores of students in the experimental group. In addition, the findings obtained from the interviews revealed that the interaction between student-instructors in SVLE increased the students' motivation and engagements into the courses compared to ASVLE. As for ASVLE, there was no evidence about the enhancements of the students of control group in terms of metacognitive awareness before and after intervention. Transactional distance and poor quality of the relationship between students and instructor caused students to give up learning L3 German.