This paper focuses on peer reviewing as part of the writing process and as a pedagogical strategy that can help students develop their writing and critical thinking skills. To do so, it examines the extent to which peer reviewing can develop English as a foreign language (EFL) students’ ability to evaluate and reflect on their writing in upper secondary school. Moreover, this study investigates whether digital tools can help to facilitate the peer review process. By reviewing and synthesizing ten empirical studies from the period 2013-2020, the study found that students who engage in peer reviewing in writing develop critical thinking skills, self-regulation and evaluation. It further shows that there is a consensus between researchers regarding the usefulness of peer review in developing critical thinking skills. However, the findings indicate the importance of including guided peer review training before peer review activities. Furthermore, there is a strong indication that digital tools can help facilitate the peer review process if used appropriately. Digital tools help engage students in the peer review process since they are able to interact with each other’s texts online. Lastly, the findings of the study are in line with the Swedish national curriculum and the English syllabus for upper secondary school. Therefore, teachers in Sweden should consider the use of familiar digital tools to engage students in peer review to develop their writing and critical thinking skills.