We studied ectoparasite infestation patterns in a wild population of brown antechinuses, Antechinus stuartii (Dasyuridae) at three sites in south-eastern New South Wales, over a period of seven months. Ectoparasite diversity on brown antechinuses was particularly high for a small mammal: 18 species of ectoparasites were recorded, including one undescribed species of mite. Ectoparasite infestation varied between study sites and changed seasonally. Variation between sites was related to habitat and environmental parameters, and the highest ectoparasite infestations were encountered in the coolest habitat with greatest depth of leaf litter. Host population densities varied only slightly between sites, and host density was not considered to be a primary factor influencing ectoparasite infestation. This is the first study to provide a host record of ectoparasites of Antechinus stuartii sensu stricto.