Abstract: The chemical composition of the essential oil obtained by hydrodistillation from Tanacetum polycephalum was analysed by GC and GC/MS and 39 compounds constituting 94.02% of the oil were identified, the major components being borneol (28.30%), β-pinene (10.10%), α-pinene (6.5%), camphene (6%), α-terpineol (5.16%) and 1,8-cineol (5.10%). The essential oil exhibited remarkable bactericidal activity against Staphylococcus aureus, Shigella flexnery, Salemonella thyphi, Staphylococcus epidermidis, Staphylococcus saprophiticus, Psudomonas aeroginosa and Escherchia coli. The antioxidant activity of the essential oil was evaluated using the DPPH test and 5-lipoxygenase test. The antioxidant activity show that, in reduction of the stable radical DPPH, the highest activity was obtained with the essential oil and with Trolox (IC50 = 12.4 and 8.9 μg mL–1, respectively).