lantana montevidensis (spreng.) briq. is a shrub native to south american countries. in congolese traditional medicine, its leaves are used as herbal tea or in steam inhalation therapy for the treatment of respiratory disorders. the goal of this study was to determine the chemical composition and the anti-sickling activity of the essential oil obtained from the leaves of this species growing wild in the democratic republic of congo. previous studies on the chemical composition of this species essential oil showed that it is mainly rich in sesquiterpene hydrocarbons such as (e)-caryophyllene, germacrene-d, (z)-caryophyllene, valencene, bicyclogermacrene, (e)-nerolidol, -selinene, sabinene, -terpinene, and -elemene in different ratios. the gas chromatography-mass spectrometry analysis of our oil revealed that it is rather rich in monoterpenes, with geranial (24.13%), neral (17.73%), limonene (8.27%), -terpinene (2.81%), p-cymene (2.36%), geraniol (2.33%), nerol (1.52%), citronellol (1.37%), linalool (1.24), and carvone (1.20%) as major constituents. germacrene d (4.21%), -elemol (3.53%), and -caryophyllene (1.08%) were the only main sesquiterpenes detected, besides 6-methyl-5-hepten-2-one (3.51%). the emmel test performed on this essential oil displayed a strong anti-sickling activity at the concentration of 625 ug/ml.