Myrciaria floribunda (H.West ex Willd.) O.Berg, Myrtaceae, popularly known as “camboim amarelo”, was collected in Restinga de Jurubatiba (RJ, Brazil). Leaves, stems and flowers were individually submitted to hydrodistillation, affording the respective essential oils. Monoterpenes were the main group of essential oils from leaves (53.9 %) and flowers (55.4 %). Sesquiterpenes were more representative in stems (72.2 %). 1,8-cineole was the major constituent in the essential oil from leaves (38.4 %) and flowers (22.8 %). The major constituent from stems was (2E,6E)-farnesyl acetate (19.9 %). To our knowledge, these are the first contributions for essential oils from stems and flowers of M. floribunda. It was also performed the acetylcholinesterase inhibitory bioassay of the essential oil from stems, flowers and leaves of M.
floribunda. Flowers and leaves oils had an IC50 of 1583 and 681 μg/mL, respectively, being both low to mild values.