The essential oil of A. zerumbet, obtained from the leaves through steam distillation, has a distinct aroma and shows antioxidant activity. In this study, we evaluated the yields, antioxidant activity, and volatile compound composition of essential oils extracted from the leaves of A. zerumbet to better understand how these characteristics may vary among individual plants, and how they may differ with location of growth and season in which leaves are harvested. Gas chromatographyâmass spectrometry (GC/MS) and principal component analysis (PCA) revealed that chemical composition in each individual plant was not affected by harvest season or growth area. Furthermore, GC/MS and antioxidant activity assays revealed that although the antioxidant activity and yield of these essential oils differed significantly between individual plants and collecting seasons, there was a strong inverse correlation between the yields of essential oils and their antioxidant activity. The yield, the major volatile compound compositions, the enantiomeric ratio of the few monoterpenes, and the antioxidant activities of A. zerumbet essential oil varied significantly among individual plants, and probably reflected the genetic variability within the species. This suggests the plausibility of selecting lineages of A. zerumbet to optimize future production of valuable essential oils.