(Uploaded by Plazi for the Bat Literature Project) Tropical West Africa has a high diversity of bats, which are relatively poorly studied. In this baseline biodiversity assessment of bats in the Simandou Mountain Range of southeastern Guinea (Guinea Forestière), 312 individual bats belonging to 26 species were captured, four of which represent new species records for the country. Combined with the results of a previous survey, 35 bat species have been recorded at Simandou to date, including a new species (Neoromicia sp. nov.), which we describe here, and an additional species potentially new to science. A neotype for Neoromicia tenuipinnis is designated. We present an annotated checklist of the bats at Simandou and neighbouring sites, including some pertinent field notes on their habitat requirements and conservation status. Furthermore, we discuss the estimated maximum species richness and show that Simandou supports one of the most diverse bat communities in tropical Africa. Finally, we outline conservation concerns with respect to bats in the face of the iron ore extraction activities at Simandou.