The antioxidant capacity of different types of red and white wines was assessed by different assays. Two assays were used to evaluate the antioxidant capacity in aqueous phase: (1) inhibition of the generation of 2,2'-azinodi(3-etilbencenotiazolin-6-sulfonate) (ABTS)-derived radical; and (2) protection of vitamin E in human plasma. The results indicated that red wines were not all equally effective, and a comparison could be made among different types. The ABTS assay showed that Cabernet Sauvignon wines had the highest antioxidant capacity followed by Malbec wines. Red wines showed a protective capacity of 70-90% in preventing SH-groups oxidation, and, in addition, they were also effective in preventing the oxidative damage in lipid domains (30-97% protection to liposomes, 20-70% to vitamin E). The antioxidant capacity of the white wines was significantly lower, as evaluated by all the assays. Significant correlations were found for phenolics and catechin content with the antioxidant capacity of the studied wines.