gc-ms analyses of the essential oils of leaves, stems and flower of nasturtium officinale resulted in the identification of 9, 8 and 15 compounds, representing 97%, 100% and 94.7% of the oils, respectively. the main compounds of the oil of leaves were myristicin (57.6%), -terpinolene (8.9%) and limonene (6.7%). caryophyllene oxide (37.2%), p-cymene-8-ol (17.6%), -terpinolene (15.2%) and limonene (11.8%) were the main components in stems, whereas limonene (43.6%), -terpinolene (19.7%), p-cymene-8-ol (7.6%) and caryophyllene oxide (6.7%) were the major constituents in the oil of flowers. all the samples were subjected to a screening for their possible antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (dpph) and -carotene-linoleic acid assays. in the above tests, methanol extracts of leaves showed higher antioxidant activity than the oils and methanol extracts of stems and flowers.