It has a single tube-shaped leaf and up to thirty five green or reddish-brown flowers with a pink to purple labellum.

Prasophyllum fitzgeraldii is a terrestrial, perennial, deciduous, herb with an underground tuber and a single tube-shaped leaf which is 100–450 mm (4–20 in) long and 3–5 mm (0.1–0.2 in) wide.

The upturned part is crinkled and there is a fleshy, purplish-green callus in the centre and extending past the bend.

[2][3] Prasophyllum fitzgeraldii was first formally described in 1909 by Richard Sanders Rogers and Joseph Maiden and the description was published in Transactions, proceedings and report, Royal Society of South Australia from a specimen collected in the Sandy Creek Conservation Park.

[6] FitzGerald's leek orchid grows in grassland, heath and forest in the south-east of South Australia.