It has a single tubular, green leaf and up to fifty scented, greenish to pinkish flowers.

Prasophyllum montanum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single tube-shaped leaf, 500–700 mm (20–30 in) long and 8–10 mm (0.3–0.4 in) wide at its purplish base.

[2][3] Prasophyllum montanum was first formally described in 1991 by Robert Bates and David Jones from a specimen collected at Mount Franklin in the Australian Capital Territory and the description was published in Australian Orchid Research.

[1][3] The specific epithet (montanum) is a Latin word meaning "of mountains"[4] referring the habitat of this species.

[3] The mountain leek orchid grows on dry rocky ridges or in forest, usually above 1,500 m (5,000 ft).