The accentuated increase in the use of medicinal plants by the population to treat diseases makes it necessary to carry out pharmacological studies in order to contribute to the scientific knowledge and clarify the mechanisms involved in the main compounds present in these plants. Due to the difficulty of combating antimicrobial-resistant microorganisms, plants become a low-cost and effective alternative. The stem, fruit, and leaves of plants are used to measure antioxidant and antimicrobial capacity and to combat the oxidative degradation of free radicals produced in the presence of xenobiotics. A systematic review is a powerful tool that incorporates the variability among the studies, providing an overall estimate of the use of plant extracts as antioxidants and antimicrobial activities. In view of the controversies in the literature regarding the use of compounds from plants or the isolation and purification of the main substances for the prevention of bacterial various therapeutic actions, the aim of this was to present a systematic review on the antimicrobial and antioxidant properties of cashew (Anacardium occidentale), cajui (Anacardium microcarpum), and pequi (Caryocar brasiliense). The following databases were analyzed: PubMed/Medline, Virtual Health Library (LILACS and SciELO), and Science Direct. Out of 425 articles, 33 articles have been used in this study, which were also represented in the Prisma Statement. In vitro antioxidant tests were conducted in 28 studies using different methodologies. Most of the tests involving the studied species demonstrated positive antioxidant potential and antimicrobial properties. The results provide important data and perspectives into the use of natural products that can contribute to the treatment of various diseases.