This paper examines how peer mentoring strengthens teaching practices in Regular Basic Education considering the changes undertaken since the COVID-19 pandemics. Peer mentoring is an in-service teacher training strategy that includes mutual collaboration, learning and monitoring. In this systematic review, we retrieved 24 articles since 2020 from Scopus (8), Web of Science (8), Dialnet (5), Google Scholar (2) and SciELO (1) to find out about the benefits of peer mentoring. Our review was guided by the PRISMA criteria. We found that educational companionship has a positive impact on reducing knowledge gaps regarding new technologies through the exchange of experiences, promotes openness to criticism, as well as the interest in learning and unlearning, supporting learning self-regulation, and guarantees consultation, reflection, and agreement between members of the teaching communities. We conclude that peer mentoring fulfilled, to a large extent, its purpose of improving teacher performance as one of the keys to educational quality.