The antioxidant activities and total phenolic contents of five different types of Yemeni honey [Acacia ehrenbergina (Salam-Tehamah), Acacia edgeworhi (Somar-Hadramout), Ziziphus Spina-christi L. (Sidr-Hadramout), Ziziphus Spina-christi L. (Sidr-Taiz), Tropical blossom (Marbai-Hadramout) ], and four types of imported origins {an American-Tropical blossom (New Orleans), an American-Orange source (Florida), Swiss-blossom, and an Iranian-Tropical blossom I were evaluated. Total phenolic contents of diluted honey samples varied from 56.32 to 246.21 mg/100g honey as Catechin equivalent by the Folin-Ciocalteu method. Four of five Yemeni honey samples contained significantly higher total phenolic content as compared with the imported honeys. Percentage antioxidant activities of diluted honey samples were assayed in vitro by the inhibition of liver homogenate oxidation mediated by FeSO4/ascorbate system. The antioxidant activity of diluted honey samples increased with increasing the levels (50 mul, 100 mul, 200 mul) of honey samples. The total antioxidant activities of diluted samples varied from -6.48% (prooxidant activity) to 65.44% inhibition. The Acacia ehrenbergina (Salam-Tehamah) had the highest antioxidant activity and total phenolic content. A positive correlation was observed between percentage antioxidant and total phenolics, which increased with the higher level of samples (R = 90.5 at 200 mul). The present study confirms that Yemeni honey contains significant source of phenolic antioxidants that may have therapeutic potential. (C) 2002 Elsevier Science Inc. All rights reserved.