Resumo. ABSTRACT The aim of this systematic review was to analyze the cross-cultural adaptation and validation processes of Borg’s Rating of Perceived Exertion Scale (6-20) and its instructions during exercise in adults and the elderly. The study was conducted using databases that include the areas of health, sports and psychology (Pubmed, ScienceDirect, Bireme (BVS), PsycINFO, SportDiscus and Scopus), and descriptors in the English and Portuguese languages were standardized for all databases ("exercise" / "exercicio", "validity" / "validade", "borg scale" / "escala de borg"; "perceived exertion" / "percepção de esforço" and "validation" / "validação"). Among the 1,488 items found, 14 articles were selected for analysis. The main findings were that cross-cultural adaptation (Cantonese and Japanese) was reported in only four articles. The lowest-scored criteria for methodological quality were related to the concept of perceived exertion, and the instructions for use and familiarization with Borg’s scale. The results indicate that the majority of the studies did not apply the cross-cultural adaptation process and additionally, that concurrent validity was the only validation method reported. Therefore, it is necessary to carry out the cross-cultural adaptation of Borg’s Scale (6-20), mainly in the Portuguese language, in addition to other types of validation in order to ensure more accurate results.