<p>The purpose of this work was to study the chemical composition and antimycoplasmic and anticholinesterase activities of the essential oil of <i>Eugenia hiemalis</i> leaves collected throughout the year. A total of 42 compounds were identified by CG, and are present in almost every seasons. Sesquiterpenes were dominant (86.01–91.48%), and non-functionalised sesquiterpenes comprised the major fraction, which increased in the summer; monoterpenes were not identified. The major components were spathulenol (5.36–16.06%), δ-cadinene (7.50–15.93%), bicyclogermacrene (5.70–14.24%) and β-caryophyllene (4.80–9.43%). The highest oil yield was obtained in summer and autumn. Essential oils presented activity against three evaluated <i>Mycoplasma</i> strains, but no activity was observed in the anticholinesterase assay.</p
