Little is known about the diets and ecology of New Guinea's 14 bandicoot species. In order to better understand the diet and digestive morphology of these marsupials, we reviewed the literature, studied the dental morphology, conducted analysis of gastrointestinal contents, and measured the digestive tracts of: Echymipera clara, E. davidi, E. kalubu, E. rufescens, Isoodon macrourus, Microperoryctes ornata, M. papuensis and Peroryctes raffrayana. These species consume a mix of fungi, insects and plant material that is broadly consistent with the omnivorous diet characteristic of most Australian bandicoots; however, morphological observations reveal variation between species that likely reflect finer-scale differences in diet. Dental morphology suggests a wider variety of diets (insectivore, omnivore, frugivore) than on the Australian mainland (mostly omnivore). Dissections and measurements of the digestive tract of seven New Guinean species indicate variation linked to diet. The relatively short caecum in all New Guinean species, but especially in E. clara and E. kalubu, is particularly suggestive of limited consumption of fibrous plant material; the relative length of the large intestine suggests variable capacity for water reabsorption. Our dietary data also suggest that some of these species also play an important role in the dispersal of hypogeous fungi.