Abstract The composition of the essential oil from leaves of Smallanthus maculatus (Cav.) H. Rob. from Costa Rica was analyzed by capillary GC/MS. Fifty-seven compounds were identified corresponding to ca. 96% of the oil. The major components were α-pinene (32.9%), germacrene D (13.7%) and β-caryophyllene (10.7%). Key Word Index: Smallanthus maculatus Asteraceaeessential oil compositionα-pinenegermacrene Dβ-caryophyllene