Gas chromatography of essential oils ofCymbopogon showed striking interspecific differences in their major constituents. The two species of lemongrass,C. flexuosus andC. pendulus contained large amounts of citral while the citronella grass species,C. nardus andC. winterianus showed comparable amounts of geraniol, citronellal and citronellol. The essential oil ofC. martini was composed only of geraniol and citronellol and was therefore quite different to the other species. The gas chromatography profiles enable the identification of various species yielding essential oils characterised by their specific constituents.