“Mabi forests” are endangered and highly fragmented tropical semideciduous forests that occur on basalt-derived soils in the upland regions of the Atherton Tablelands, Queensland. While Mabi forest flora and fauna are generally well-described, species lists of localised remnant patches, which can provide important information for landowners managing such patches, are lacking. We studied an eight hectare (21 acre) privately-owned Mabi forest remnant in East Barron between late March to mid-April 2025. We surveyed vascular and non-vascular plants, conducted leaf litter collections and baited pitfall trapping for ground invertebrates, and light-sheeting for   nocturnal invertebrates. To survey birds and other vertebrates we undertook non-intrusive daytime and nighttime observations. To complement our dataset, we compiled the available bird and mammal data for the patch from the Atlas of Living Australia. The combined plant and animal diversity documented is significant considering the small size of the Mabi forest patch, and included bryophytes (33 spp.), ferns (15), flowering plants (152), invertebrates (192), birds (123), other vertebrates (12), protozoans (3), protists (1), and fungi (66). Of these, at least 14 plant and three animal species are of conservation significance in Queensland. Although the sampling was intensive, some groups of organisms such as fungi and invertebrates remain under-represented, and our survey data should be considered as a snapshot of the biodiversity of these groups. We conclude that remnant forest patches can provide important habitat for multiple species, and we recommend similar surveys of other Mabi forest localities and remnants of other forest types on the Atherton Tablelands to better understand the distribution of native biodiversity in these habitats.