The purpose of this study was to investigate the characteristics of online students' cognitive presence in a peer-facilitated discussion environment, and to identify the peer facilitation techniques that can enhance cognitive presence development. In this study, 738 discussion messages were examined by both qualitative and quantitative content analysis. It was revealed that although cognitive presence was detected in most discussion messages, it was exhibited at a relatively lower level. The involvement of peer facilitators was found to correlate with students' higher-level cognitive presence. It was found that asking initiating questions of a specific type by peer facilitators can positively affect the level of cognitive presence. In addition, a variety of the peer facilitation techniques were systematically studied to identify their effects on students' cognitive presence.