This study examined students' perceptions of peer feedback and learning in a large, undergraduate course that incorporated supplementary online discussions. Peer feedback (PF) was facilitated via an automated rating system, within Blackboard discussion forums, for half of the students enrolled in the course. Following the peer feedback process, students in the PF group perceived higher levels of confidence and comfort for posting and responding in online discussions than students who did not receive peer feedback. A significant difference was noted on perceptions of confidence for contributing relevant ideas to the discussions, with the PF students expressing higher levels of confidence, yet not all students perceived benefits to their learning. Implications for the implementation of peer feedback in online and blended courses are provided. (Contains 3 figures and 2 tables.)