Abstract Essential oils were obtained from fresh aerial parts and air dried flower heads of Bidens tripartita L. (As-teraceae). Volatile constituents of the oils were analyzed by GC and GC/MS methods. The 77 components were identified representing 98.5% and 80.9% of the total components detected, respectively. The major constituents of the oil of flower heads were p-cymene (16.6%), Î²-caryophyllene oxide (6.0%) and humulene epoxide II (5.3%). The main constituents of the oil of fresh herb were allo-ocimene (38.3%), (Z)- Î²-ocimene (30.6%) and Î±-phellandrene (8.5%).