The Vondrozo-Midongy rainforest corridor in south-eastern Madagascar is an example of a habitat corridor between otherwise disconnected protected areas, and is therefore considered important for the conservation of the endemic biodiversity of the island. Through several years of collaboration with local communities surrounding this corridor, WWF-Madagascar learned that members of some of these communities claimed the existence there of the black-and-white ruffed lemur (Varecia variegata) and the greater bamboo lemur (Prolemur simus), both regarded as Critically Endangered by the IUCN and not known by the scientific community to be present in the corridor. We therefore surveyed six sites in three communes in May 2010 to confirm this information. We made direct observations of Varecia variegata at two sites, which represent a southern extension to the known range of the species. We also found the characteristic feeding remains of Prolemur simus in the three most southerly sites, observations which also represent a major southern extension of the known range of this species. However, the feeding signs we found were old, at least a year old by our estimations, so we recommend further research to ascertain whether the population still exists there. The corridor is threatened by many anthropogenic pressures, and further reinforcement of the conservation program for the corridor is therefore likely to be necessary to ensure the viability of endangered lemurs in the region, and the role of the corridor in ensuring biological connectivity between the more substantial forests to the south and north.