It is universally acknowledged that learners are encouraged to construct their own knowledge through project-based learning as this teaching method reinforces their critical thinking, active learning, independent work, and/or collaboration. This paper, therefore, aimed to investigate how ninth graders at a Ho Chi Minh City-based bilingual school self-evaluated their autonomous learning skills during the use of project-based learning in a Media course. Thirty-five students were involved in responding to a questionnaire and writing diaries, and six of them participated in semi-structured interviews. Descriptive statistics in terms of mean and standard deviation was opted for processing the quantitative data from the questionnaire while content analysis was used to analyze the qualitative data garnered from the interviews and diaries. The quantitative results showed quite high mean scores, i.e., the surveyed students were able to conduct autonomous learning skills during the project-based Media class. The findings further indicated the development of autonomous learning skills (e.g., making plans for project fulfillment, self-overcoming the learning challenges, expressing more ideas, and self-assessing their learning capacity) rated by the participants. However, other skills such as goal setting and self-monitoring remained unchanged.