This study documents the parasite assemblage of Rattus colletti (Thomas, 1904) from the Adelaide River flood plain, Northern Territory, Australia. In total, six species of helminth (comprising two cestodes, one trematode and three nematodes), and four species of arthropod (comprising one tick, one mite, one flea (identified to family level) and one louse (identified to generic level)) were found. In spite of the hosts being present in high numbers the helminth assemblage was depauperate, characterised by low prevalence and abundance, both being higher in wet seasons. More helminths were found in larger animals. The most prevalent helminth was from the Trichostrongylina, Nippostrongylus typicus (Mawson, 1961). The assemblage was characterised as having two heirloom species (N. typicus and Hymenolepis diminuta (Rudolphi, 1819)), a host capture (Raillietina celebensis (Janicki, 1902) and a cosmopolitan species (Mastophorus muris (Gmelin, 1790)) as well as occasional infections. When compared with the helminths from a single population of Rattus sordidus (Gould, 1858) a similar number of species were found, three species being in common, and both were depauperate when compared with the more extensively surveyed faunas of Rattus fuscipes (Waterhouse, 1839) and Rattus leucopus (Gray, 1858).