The antioxidative activities of the ethanol and aqueous extracts of the leaf and root samples of Albizia antunesiana were determined across a series of four in vitro models. The results showed that all the extracts had reducing power (Fe(3+)- Fe2+), DPPH, hydroxyl and nitric oxide radical scavenging abilities. The ethanol root extract had more potent antioxidant power in all the experimental models and possesses a higher total phenol content of 216.6 +/- 6.7 mg/g. The GC-MS analysis of the aqueous and ethanol extracts of the roots and leaves indicated that several aromatic phenolic compounds, a coumarin and some common triterpenoids were present in these extracts. Data from this study suggest that the leaves and roots of Albizia antunesiana possessed antioxidative activities that varied depending on the solvents.