The essential oil isolated from Asarum cordifolium C. E. C. Fischer recently discovered in Vietnam, and A. glabrum Merr., an endangered species listed as vulnerable in the Red Data Book of Vietnam, have been analyzed by a combination of chromatographic and spectroscopic techniques including 13C NMR spectroscopy. The composition of A. cordifolium essential oil, investigated for the first time, was dominated by elemicin (82.5%). The essential oil isolated from A. glabrum contained safrole (41.9%) as its major component and was characterized by the diversity of phenylpropanoids contained in this oil (10 compounds).