One cestode and 3 species of nematodes are recorded from Pseudohydromys murinus and Pseudohydromys occidentalis (Muridae: Hydromyinae), from Papua New Guinea, for the first time. Heterakis fieldingi (Ascaridida: Heterakidea) has previously been known from Australia. Odilia sp. resembles Odilia praeputialis in the orientation of the synlophe and the number and size of ridges but differs in the length of spicule and lack of a praepuce. Protospirura kaindiensis n. sp. (Spirurida: Spiruridae) is readily distinguished from all other members of the genus by the number and arrangement of caudal papillae and the length of the spicules.