In this study, water-distilled essential oil of three species of Acinos Miller (Lamiaceae) were analysed by GC-MS. Oils from A. suaveolens (Sm.) G. Don fil. were found to contain pulegone (23.2-80.7%) and isomenthone (1.1-54.1%). Oils from A. arvensis (Lam.) Dandy and A. rotundifolius Pers. were found to contain germacrene-D (14.3% and 14.4-73.1%) hexadecanoic acid (14.0% and 17.5-30.2%). Copyright (C) 1999 John Wiley & Sons, Ltd.