The genus Austraplectana Baker, 1981 is a poorly known group of cosmocercoid nematodes. In the present study, a new species of Austraplectana, A. extranes sp. n., was described using both light and scanning electron microscopy, based on specimens collected from the carbine barred frog Mixophyes carbinensis Mahony, Donnellan, Richards & McDonald (Anura: Myobatrachidae) and the cane toad Rhinella marina (Linnaeus) (Anura: Bufonidae) in Australia. Austraplectana extranes sp. n. can be easily distinguished from its congener by the much longer and different morphology of tails in both sexes, the different number and arrangement of caudal papillae, the presence of single precloacal median heart-shaped papilla and large posterior protuberance with cuticular comb-like fringe in male.