Situated in the field of computer assisted language learning (CALL), this article reports an instrumental case study on the use of audioblogs for developing students' Chinese speaking skills. The intervention focused on scaffolding students in metacognitive reflection of their oral performances. The case focused on seven students who completed substantial part of the activities, and the main sources of data came from the oral recordings and interactions in their audioblogs. A significant improvement in the mean scores of pre- to post-test oral performance was found, which indicated the benefits of this approach. The students were found to adopt a systematic approach in their reflection: evaluating [arrow right] monitoring [arrow right] planning, with greater amount of attention devoted to the monitoring strategy. However, a disproportionate distribution of metacognitive knowledge usage was found in students' self-assessment. Task knowledge was the predominant metacognitive knowledge used by students, whereas person knowledge and strategy knowledge were neglected by the students. Teachers who are keen to implement a similar instructional approach could develop strategies to focus the students' attention on the latter two types of metacognitive knowledge. (Contains 8 tables and 2 figures.)