Sixteen major components have been detected in woody tissues of Eucalyptus polyanthemos. The components identified include 2,3- and 4,6-(hexahydroxydiphenoyl)~glucose, a di-(hexahydroxydiphenoyl) glucose known as pedunculagin, an ellagitannin which appears to be a cyclic di-(hexahydroxydiphenoyl) diglucose, 3,4,3'-tri-0-methylellagic acid and its I'-glucoside, 3,4,3',4'-tetra-O- and 3,3'-di-0-methylellagic acids. A 3,3'-di-0-methylellagic acid glucoside and 2 gallotannins are possibly present in addition to the unidentified ellagitannin D-13. The distribution of these components in the woody tissues is discussed in relation to heartwood formation. The trimethylellagic acid glucoside was also present in the heartwood of other members of the red-box group of eucalypts.