It has a single tubular, green leaf with only a short free section and up to fifty scented, yellowish-green flowers.

The labellum is egg-shaped to lance-shaped, up to 8 mm (0.3 in) long, turns upwards and has wavy, wrinkled edges.

[2][3][4] Prasophyllum flavum was first formally described in 1810 by Robert Brown and the description was published in Prodromus Florae Novae Hollandiae et Insulae Van Diemen.

[6] The yellow leek orchid grows in moist, fertile soils in high-rainfall forests.

It is found on the coast and ranges of New South Wales and in Victoria south-east Queensland and in Tasmania.