Higher education focuses on promoting the training of autonomous, critical professionals who adapt to the ever-more demanding labor market. To achieve these objectives, it is necessary to rethink teaching practices in order to allow the student to be the main actor and modeler for their learning process. Previous studies based on Vygotsky's sociocultural theory have shown that learning should be treated as a socio-cultural activity. Indeed, according to this approach, individual knowledge is firstly constructed at a social level. Peer review, for its part, is a learning tool based on the sociocultural approach. It allows students to achieve higher levels of autonomy and critical thinking. This research's aim is, on the one hand, to analyze the effect of peer review on the quality of academic essays and, on the other, to examine the way in which linguistic and communicative competence in academic writing are affected. This experimental study was carried out with 68 level B1 + students (32 men and 36 women) in a private university in Ecuador during one academic year. After the statistical analysis, it is concluded that peer review has a positive impact on academic writing. However, the impact is higher in the communicative competence than in the linguistic competence. This result is aligned with previous research, which shows that students tend to prioritize message over form. Future research should investigate peer review's long-term impact upon students and their ability to transfer skills acquired in English class to other subjects, or even to professional contexts.