ABSTRACT The essential oils of Ageratum conyzoides L. obtained by hydrodistillation of fresh flowers and a combination of leaves plus stems were analyzed by GC and GC/MS. The main components of the flower, leaf and stem oils were Î²-caryophyllene (14.35% and 17.00%), 6-demethoxy-ageratochromene (30.30% and 26.60%) and ageratochromene (34.90% and 36.90%) respectively.