Tree 30‒40m tall and 1m d.b.h., with a clear cylindrical bole to 18m; crown conical or rounded, becoming more open and irregular when mature. Bark smooth or rough with exfoliating scales peeling in irregular flakes, grey when mature.
Leaves (mature) almost opposite, narrowly ovate-elliptic, 4.5‒7 x 0.8‒1.2cm leathery, multiveined, glabrous, apex obtuse, pale green or glaucous.
Male pollen-cones axillary, solitary, cylindrical, 2.5‒3 x 0.6‒0.9cm, with 4-8 pairs of overlapping bracts at their base, each pair at right angles to the pair next above or below, peduncles thick, 8‒12mm. Female seed-cones solitary, globose,10‒15 x 9‒12cm , green or glaucous green, brown when mature, very resinous. Seeds 15‒20 x 8‒10mm, with two unequal wings.
In this assessment, Agathis corbassonii is included with A. moorei. A. corbassonii was originally segregated on the basis of its very reddish brown bark and its narrow leaves which are often glaucous beneath. However, a recent revision (T.G. Waters, unpublished D.Phil thesis, Oxford 2008) strongly indicates that these characters are related to environmental conditions. Other characters such as numbers of bract scales in pollen cones fall within the range of those described for A. moorei (Farjon, 2010).