Durikainema macropi gen. et sp. nov. (Muspiceoidea : Robertdollfusidae) is described from the mesenteric and hepatic portal veins of Macropus giganteus Shaw 1790, M. agilis (Gould 1842) and M. rufogriseus (Desmarest 1817) (Marsupialia : Macropodidae) from Queensland, Australia.It is also known from histological sections of hepatic portal veins of M. robustus Gould 1841, M. fuliginosus (Desmarest 1817) and Lagorchestes conspicillatus Gould 1842. The new genus resembles the Enoplina in cephalic and caudal characters and the Dorylaimina in other characters. Durikainema resembles Robertdollfusa Chabaud and Campana 1950 in its small form, absence of mouth oesophagus and anus, atrophied digestive tube, reduction of female genital apparatus to a uterine pouch, viviparity and cephalic cuticular inflation in larvae.It differs from this genus in its complex and welldeveloped cephalic structures and its welldeveloped body musculature in both sexes. Durikainema is tentatively placed in the Robertdollfusidae, Muspiceoidea. Larvae develop beyond firststage in the uterus of the female. They have been found in the non-peripheral blood of male and female M. giganteus, the lactating mammary gland of female M. agilis but not the non-lactating glands of the same female and in the deep capillaries of thigh skin of male M. agilis. Transmission of the parasite may be direct by a percutaneous or milk route, or indirect by a haemophagous arthropod.