Abstract: This paper reports on a bat survey conducted in November 2011 in Mangolo Nature Park and Rawa Aopa Watumohai National Park, both lowland forests located in Southeast Sulawesi. We recorded 22 species of bats that represents nearly 1/3 of the total bat species known to occur on Sulawesi. Three of these are endemic to Sulawesi and adjacent islands, whereas one species, Myotis cf. ridleyi was identified as a new distributional record for this island and with further investigation could prove to be an undescribed species. Our record of Chironax melanocephalus tumulus provided a range extension to the southeastern arm of Sulawesi. Two specimens of Hipposideros boeadii were topotypes and represent the first collections after the description of the type specimen. Collections of Rhinolophus arcuatus from this survey were only the second record of this species from island and represent a range extension. Specimens of Megaderma spasma celebensis were the first records of this species from Southeast Sulawesi. Species are discussed individually with external, cranial and dental measurements summarized. Based on this survey, the number of bat species now documented from the lowlands of Southeast Sulawesi represents the highest diversity yet recorded from a site on Sulawesi. This region is therefore a high priority for conservation and a hotspot for bat research in Indonesia, especially Sulawesi.