Camera traps are standard tools for assessing populations of medium–large terrestrial mammals, particularly for rare, elusive or cryptic species, yet few researchers have attempted to employ camera traps to document rare primates in arboreal settings. We examined different arboreal camera-trap techniques to document the Critically Endangered greater bamboo lemur Prolemur simus in Madagascar. We documented P. simus at two sites, confirming presence at one site. Most species, including 86% of all lemur occurrences, were documented in low light conditions (c. < 105 lux). Our study suggests that camera traps can be effective in validating unconfirmed sightings of rare or secretive primate species. We recommend that future work with cameras in arboreal settings considers seasonal activity patterns, targets sites with high food densities, uses local knowledge, and utilizes available techniques (e.g. traditional trapping techniques) and landscape topography to concentrate animal movement (e.g. steep slopes or ridge lines).