The search for new bioactive substances derived from natural products is daily growing. Among biologically active products used in therapeutic approaches, essential oils are described with wide range of therapeutic and pharmacological potential. Plants from Myrtaceae family have the presence of essential oils in its composition. Calyptranthes grandifolia, Calyptranthes tricona and Myrciaria plinioides species belong to this family and are used by the local population. However, there are no reports in the literature describing relevant characteristics about the potential and possible activities of these species. The aim of this study was to identify the main compounds, evaluate the antioxidant potential and investigate, in RAW264.7 and CHO-K1 cells, the cytotoxic activity of the essential oils from the leaves of C. grandifolia, C. tricona and M. plinioides plants, in order to ensure their use. The compounds were identified by GC–MS, antioxidant activity was determined by DPPH method and cytotoxicity was assessed by the Alamar Blue method, at 48 and 72h. The main compounds found in the essential oils were sesquiterpenes. None of the essential oils have antioxidant potential. In cytotoxicity assays, the essential oils from the plants in analysis showed moderate activity in the proposed conditions. The alterations observed between the data provided by the essential oils in question, between different cell lines, may be associated with their composition, suggesting action of minor compounds. These results may suggest that the essential oils from C. grandifolia, C. tricona and M. plinioides have considerable potential to be explored. Future studies will be conducted to obtain more information about the action pathway and potential of the identified compounds.