<jats:title>Abstract</jats:title> <jats:p>Polyphenols in heartwood, sapwood, and knots of <jats:italic>Acacia crassicarpa</jats:italic> and <jats:italic>Acacia mangium</jats:italic> were analysed using GC, GC-MS, HPSEC, and NMR. Melacacidin and isomelacacidin dominated in <jats:italic>A. crassicarpa</jats:italic> and teracacidin and its ketone in <jats:italic>A. mangium</jats:italic>. Also, bi- and triflavonoids were tentatively identified in the samples. The amounts of polyphenols were larger in the knots than in the heartwood of both species, while the composition within the species was the same.