Peer feedback is considered as an important dominant tool in enhancing the process of learning English writing. It also is regarded as a social activity. Some researchers consider peer feedback as an ineffective technique for improving students' writing and prefer teacher feedback to peer feedback. But ample of researchers have claimed that peer feedback in writing classes is useful because of the cognitive, and social benefits of peer feedback. The present article seeks to briefly summarize some of the main arguments in favor and against the role of peer feedback in learning second language writing.