The purpose of this paper is to investigate the effects of students’ peer feedback in collaborative English writing of general English classes. For this reason, online pre-and post-surveys were conducted on 33 students enrolled in D University in Chuncheongnam-do. The study results showed that in terms of the affective aspects of peer feedback, the burden of providing feedback, anxiety about English proficiency and negative feedback, and discomfort with negative feedback decreased. At the same time, the perceived usefulness of peer feedback increased. However, cooperation and responsibility, trust in peer feedback, motivation, and the burden of interaction did not show statistically significant differences. In addition, students mentioned that they benefited from peer feedback in the order of grammar, text structure, and vocabulary. As positive aspects, they highlighted objectivity, assistance in English learning, and increased confidence. On the other hand, they pointed out their discomfort in giving feedback due to their low English proficiency and the possibility of providing incorrect information. Based on the results, several implications are discussed.