The Critically Endangered Leadbeater’s possum is a small, cryptic, arboreal marsupial largely restricted to the montane ash forests of Victoria, Australia. To rapidly locate colonies of Leadbeater’s possum for protection from timber harvesting, we adapted an arboreal camera trapping approach to survey 289 sites across the species’ range from 2014-2016. We worked with arborists to place cameras set opposite bait stations in trees up to 47 m above ground. Two or three Reconyx cameras (models HC500, HC600 or PC900) were used per site, located < 150 m apart, for 3–4 weeks duration. The large survey effort using a standardised method allowed modelling of detection probabilities for Leadbeater’s possum. We examined the effects of survey length, number of cameras per site, season, camera model and camera height. Covariates including camera height, tree height, and season had a negligible influence on detectability. Detection probabilities associated with the three different camera models were generally similar. Survey length and number of cameras had the greatest influence: after 21 days of sampling with a single camera, detection probabilities were 0.37–0.54. After 28 days sampling with three cameras per site, detection probabilities increased to 0.87–0.95. Deployment of three baited camera traps for at least four weeks result in a very high probability of detecting Leadbeater’s possums at sites where they occur. These findings have led to a more efficient method of locating Leadbeater’s possum colonies, improving conservation management of this species.