The composition of the essential oil (EO) from leaves of Vernonia polyanthes and the evaluation of its leishmanicidal potential are reported here for the first time. The oil obtained by hydrodistillation was analysed by combination of GC and GC/MS. Thirty-five compounds were identified, representing 91.8% of the oil composition. The oil consists primarily of monoterpenes (37.1%), sesquiterpenes (26.3%) and oxygenated sesquiterpenes (23.9%), myrcene (34.3%), zerumbone (15.8%), bicyclogermacrene (8.9%), α-humulene (4.8%) and germacrene D (4.3%) being the major constituents. Activity against Leishmania infantum was determined using the tetrazolium dye (MTT) colorimetric method. The oil, as well as zerumbone, one of its major constituents, showed significant leishmanicidal activity, with IC values of 19.4 and 9.0 μg/ml, respectively. Cytotoxicity in macrophages cells was evaluated using the MTT colorimetric assay. The EO showed the CC < 10 μg/ml to macrophages cells.