This work provides a mapping of studies concerning Peer Instruction (PI) in the teaching of chemistry. To this end, a systematic review was undertaken of how PI has been implemented and investigated in chemistry classes, as well as the impact of PI on the learning outcomes of students. The review covers the period from 1991 to 2022. The reported studies were mainly conducted at higher education institutions, at public universities in England, Turkey, the USA, and Brazil. In chemistry courses, the PI method was implemented in subareas such as general chemistry, physical chemistry, and analytical chemistry. Some studies adapted PI to online courses, while others compared different types of peer groups and investigated the influence of different factors on PI, such as pre-class reading and showing live voting results. The effectiveness of PI varied depending on the way it was implemented, such as in peer grouping, online activities, or presential classes. The outcomes of PI in chemistry classes have mainly been monitored by means of the perceptions of the students, with performance in answering conceptual questions frequently being used as an assessment tool. This review found only a few studies concerning PI in chemistry, particularly in high school chemistry classes. Additionally, pre-class activities were not widely employed. Most of the articles utilized quantitative analysis and indicated positive outcomes for the learning process.