The antiradical properties of essential oils and extracts from the clove bud (Eugenia caryophyllata Thumb.) and berries of tree (Pimenta dioica (L.) Meriff) were studied and compared with the properties of synthetic antioxidant ionol (2,6-ditret-butyl-4-hydroxytoluene, BHT) in model reactions with the stable free 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. The essential oils of clove bud and pimento had qualitatively close composition of the main components but differed by their quantitative content. In the studied samples, eugenol was the main compound with high antiradical activity. The reaction rates of essential oils and extracts with the DPPH radical were practically the same for essential oils and twice the reaction rate of BHT. The values of antiradical efficiency (AE) were also close for essential oils and were twice that for extracts and ionol. A synergetic action of components in the essential oil and extract of pimento on antiradical efficiency values was found.