Plants slender up to 35cm tall. Leaves 3-4 - spaced up the stem - oblong to linear up to 18cm long. Bracts ovate-acute. Inflorescence slender - sepals lime-green - petals and lip rich yellow. Lip deltate (triangular) - acute. Superficially similar to Pterygodium catholicum but is found in wetter habitats. The flower colour of Pterygodium acutifolium is usually a richer butter-yellow and older flowers do not turn red as in Pterygodium catholicum.