The Critically Endangered Leadbeater’s possum is a small, cryptic, arboreal marsupial restricted to the montane ash forests in Victoria, Australia. Threats to this species include extensive bushfires and timber harvesting. To rapidly locate new possum colonies to implement conservation actions, we have undertaken broadscale surveys across the species range, using remote cameras mounted in trees to detect Leadbeater’s possums at night while they are foraging. The major challenge of camera trapping for this species is they rarely come to ground and they are non-gliding, so foraging occurs only in densely connected layers of the forest. This layer varies in height with forest age. To overcome these issues, cameras were installed using specialist arborists, allowing us to be flexible when surveying across forest age-classes. From November 2014 to April 2016 we surveyed 289 sites, resulting in 18,581 camera trap-nights and over 466,000 images. Leadbeater’s possums were detected at 148 (51%) of these sites. They were recorded in all sampled forest age-classes, including fire regrowth from major bushfires in 1939 and 1983, and timber harvesting regrowth. All new colonies have now been protected with a timber harvesting exclusion zone, resulting in 1,865 ha of forest reserved. Arboreal camera trapping has proven effective at detecting Leadbeater’s possum and has allowed a large number of sites to be surveyed to inform and improve its conservation management. Arboreal camera trapping is a potentially useful technique for anyone conducting research on arboreal mammals.