Araucaria columnaris is a distinctive narrowly conical tree growing up to 60 m (200 ft) tall in its native habit. The trees have a slender, spire-like crown.ü

The shape of young trees strongly resembles A. heterophylla. The bark of the Cook pine peels off in thin paper-like sheets or strips and is rough, grey, and resinous.

The relatively short, mostly horizontal branches are in whorls around the slender, upright to slightly leaning trunk. The branches are lined with cord-like, horizontal branchlets. The branchlets are covered with small, green, incurved, point-tipped, spirally arranged, overlapping leaves. The young leaves are needle-like, while the broader adult leaves are triangular and scale-like.