We investigated the diets of five forest-dwelling species of dasyurid marsupials endemic to New Guinea by using faecal and gut content analysis and compared the contents with the results of pitfall trapping for terrestrial invertebrates carried out coincidently. In one study area, in montane forest 2060–2340 m above sea level, three dasyurid species were trapped. In another area, in forest 1000–1470 m above sea level, two other species were captured. All five species ate a diverse range of invertebrates but beetles (Coleoptera) and spiders (Araneae) formed the bulk of their diet, followed by grasshoppers and crickets (Orthoptera). Earthworms (Annelida) were eaten by all species and some vertebrate remains were found in samples from four species. We found some significant differences between diets of the sympatric species. Some of the invertebrates commonly collected in pitfall traps, such as isopods (Isopoda) and amphipods (Amphipoda), were rarely detected in the diets of any of the species and millipedes (Diplopoda) and centipedes (Chilopoda) were never detected. Our results are broadly in agreement with what is known about the diets of the small Australian species of dasyurid marsupials.