The aim of the present study was to analyzed chemical constituents of the essential oil, obtained by hydro distillation of the roots of Crassocephalum crepidioides (Benth.) S. Moore. The oil was analyzed using gas chromatography equipped with flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Forty-seven compounds were identified, representing 93.2 % of the total oil. The main constituents were (E)-beta-farnesene (30.6%), alpha-humulene (10.3%), beta-caryophyllene (7.2%), cis-beta-guaiene (6.1%) and alpha-bulnesene (5.3%). The oil was constituted mainly of sesquiterpene hydrocarbons (77.6%), followed by oxygenated sesquiterpenes (8.7%), oxygenated monoterpenes (3.5%), monoterpene hydrocarbons (2.8%) and phenyl derivatives (0.6%). This is the first report on the essential oil composition of the roots of C. crepidioides.