Recent studies on peer review groups in second language classes have focused on various topics, including collaboration (Carr, 2008) and the effect of peer review versus teacher feedback on students' writing (Zhang, 1995). One area that has received little attention is the content of students' speech during peer review. This longitudinal case study examined English as a second language (ESL) students' oral discourse during peer feedback sessions to explore the types of comments ESL students choose to make during peer review sessions. The study was conducted between fall 2009 and summer 2010 at a large urban university in the southeastern United States. Data collection included audio-recorded peer review sessions, interviews with the teacher, and the researchers' observation notes. The researchers thoroughly analyzed the content of the students' discourse during actual peer review sessions. The findings of the study shed light on various aspects of writing ESL that students choose to comment on during peer feedback sessions. The findings may serve as the basis for further research on students' discourse during peer review, teachers' feedback or facilitation of peer review sessions, and issues of collaboration in peer review sessions in ESL classes.