Pterostylis truncata is classed as endangered under the Victorian Government Flora and Fauna Guarantee Act 1988. Populations are only known from the You Yangs, Black Hill Reserve near Ballarat and the Long Forest Nature Conservation Reserve near Bacchus Marsh although the range of the orchid was once considerably larger. The main threats to the species and factors in its decline in Victoria, include grazing by European rabbits (Oryctolagus cuniculus), feral goats (Capra hircus) and eastern grey kangaroos (Macropus giganteus), as well as weed invasion, especially boneseed (Chrysanthemoides monilifera) and habitat loss due to urbanisation.