This paper investigates the autonomous learning strategies employed by students while participating in extensive reading (ER) and their perception of this method. Semi-structured interviews and autonomy strategies questionnaires are used as research instruments. The 25 participants are freshmen majoring in English. The findings illustrate some favored autonomous strategies that students used, such as summarizing, making inferences, taking notes, and using imagination. It is noticeable that using translation is an uncommon strategy chosen by these participants, which is somewhat unexpected in the Vietnamese context where students prefer it the most. For metacognitive and effective strategies, a sense of responsibility and monitoring received the most attention from the students. This result shows a positive attitude among the students in claiming that their autonomous learning can be enhanced via completing book reports. The findings from the current study provide insights into the implementation of book reports in extensive reading to enhance learner autonomy.