The chemical composition of the hydro-distilled essential oil from leaves of Curcuma aromatica Salisb. was analysed by GC-MS. Twenty-three compounds representing 94.29% of the total oil were identified. The antioxidant activities of the oil and various extracts of C. aromatica were evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical-scavenging assays. The oil and methanol extract showed potent DPPH radical-scavenging activities (IC(50)=14.45 and 16.58 microg/ml, respectively), which were higher than butylated hydroxyanisole (IC(50)=18.27 microg/ml). The extracts also exhibited remarkable superoxide radical-scavenging activities (IC(50)=22.6-45.27 microg/ml) and the activity in the methanol extract was superior to all other extracts (IC(50)=22.6 microg/ml). Furthermore, the amount of total phenolic compounds was determined and its content in ethyl acetate extract was the highest as compared to other extracts. The results indicate that the oil and extracts of C. aromatica could serve as an important bio-resource of antioxidants for using in the food industries.