The essential oils, obtained by hydrodistillation from the stems and leaves of Mikania sp. nov., were subjected to GC/MS analysis. Thirteen monoterpenes and eight sesquiterpenes were identified with α-pinene (24.8–23.6%) and β-pinene (48.3–61.9%) as major components. Adsorption chromatographic separation of the crude leaf oil allowed the characterization of five components by GC and H- and C-NMR, one of which (rrans-pinocarveol) was identified only by this methodology.