Raillietnema nanus n. sp. from the intestines of the skink Carlia mysi (Scincidae) from Morobe Province, Paupa New Guinea, is described and illustrated. It is the 23rd species assigned to the genus and first species of Raillietnema to be reported from the Australian biogeographical realm. It is the ninth species with a lizard type host and is distinguished from other species by its short body length, small egg size, and number of caudal papillae in the male. An initial parasite list of R. nanus and the nematode Physalopteroides milnensis is established for C. mysi.