Acer oblongum is a medium-sized evergreen to semi-deciduous tree reaching a height of approximately 15–22 metres (49–72 ft).

Leaves are opposite, ovate-lanceolate with entire margin, with a petiole 5–12 cm long, with glaucous-green underside and dark green upperside.

The flowers are hermaphroditic, small and inconspicuous, about 4 mm, greenish white, gathered in hairy racemes.

The fruits are represented by the typical two-winged samaras, about 2.5 cm long, wind dispersed.

[2] Acer oblongum prefers humid climate of the Himalayan forests, especially along streams, at an elevation of about 600–2,000 metres (2,000–6,600 ft) above sea level.