Although peer review, in which students evaluate each others' papers, has been shown to be beneficial in many writing classrooms, the benefits of peer review to the reviewer, or the student giving the feedback, has not been thoroughly investigated in the field of second language (L2) writing. The purpose of this study is to determine which is more beneficial to improving student writing: receiving or giving peer feedback. The study was conducted at the English Language Center (ELC) at Brigham Young University (BYU). Ninety-one students in nine writing classes at two different proficiency levels, high beginning and high intermediate, participated in the study. The treatment groups reviewed anonymous papers, but received no peer feedback over the course of the semester, while the control groups received feedback, but did not review other students' papers. Writing samples collected at the beginning and end of the semester were used to evaluate which of the two methods most helped student writers. In addition, a short survey was conducted to investigate the correlation between student attitudes and demographic information and these results. Results of a series of t-tests indicated that the treatment groups, which focused solely on reviewing peers' writing, made more significant gains in their writing over the course of the semester than the control groups. These results were also more significant at the lower than the higher proficiency level. Students? level of comfort with the writing process and desire to learn how to use feedback were found to be significant predictors of these results.