We compared the antioxidative activities of polyphenol metabolites with those of intact functional polyphenols by an assay of the oxygen radical absorbance capacity (ORAC). The metabolites of ellagitannin geraniin, chlorogenic acid, and (-)-epigallocatechin gallate displayed more potent antioxidative activity than their respective original compounds. Our findings suggest that these metabolites may play important roles as biological antioxidants after their consumption.