ABSTRACT Peer editing enhances critical thinking, improves student writing, ultimately leading to a more productive learning environment (Kostopoulou and O’Dwyer 2021; Lundstrom and Baker 2009, “To give is better than to receive: The benefits of peer review to the reviewer’s own writing.” Journal of Second Language Writing 18:30–43; Storch 2018, “Written corrective feedback from sociocultural theoretical perspectives: A research agenda.” Language Teaching 51 (02): 262–277; Yao et al. 2021, “How university EFL writers’ beliefs in writing ability impact their perceptions of peer assessment: Perspectives from implicit theories of intelligence.” Assessment & Evaluation in Higher Education 46 (1): 151–167). However, reservations toward peer feedback in a university EFL setting persist due to the accuracy of L2 feedback (Braine, 2003; Erdel 2023, “Student feedback literacy (SFL) profiles in an L2 writing classroom and the influence of peer feedback on the SFL features.” International Journal of Education and Literacy Studies 11 (3): 112–125.). This study utilized a pretest-posttest writing assessment to analyze differences in writing outcomes in an academic research writing course at two universities in Seoul, South Korea. The researchers also examined the accuracy of the L2 peer-editing feedback. The sampling consisted of five randomized classes of university undergraduates. Two control groups received feedback via the instructor and two experimental groups received peer-editing feedback. A fifth mixed group was divided between the control and experimental groups but within the same context. The instructors used both in-class and online feedback tools for the control and experimental groups. The analysis used Sengupta’s (1998, “Peer evaluation: ‘I am not the teacher’.” ELT Journal 52 (1): 19–28) revision taxonomy to assess peer feedback accuracy. Participants completed separate pretest and posttest writing assessments. One at the start of the semester (pretest) and one at the end (posttest). The researchers used a MANOVA to compare the pretest and posttest mean average assessment scores between the control and experimental groups. The results show that peer feedback matches the effectiveness of professor feedback for pretest/posttest scores. Researchers also assessed 156 peer-editing assignments for feedback accuracy. Peer editors demonstrated statistically significant accuracy. This study recommends using peer feedback for its benefits to L2 learners and instructors.