ABSTRACT Species of Falsocis are very distinct from members of other ciid genera and are relatively uniform morphologically. The genus has been recorded only from well preserved forests in the Neotropical region, from Costa Rica to southern Brazil. We describe Falsocis sooretama sp. nov. based on adult individuals collected at Reserva Biológica de Sooretama (Sooretama, state of Espírito Santo), a conservation unit of the Atlantic Forest biome. Falsocis sooretama sp. nov. is closely related to F. occultus Lopes-Andrade & Lawrence, but differs from it in possessing sparser stout bristles and very minute setae (~0.01 mm) on elytra, and apex of anterior male pronotal plate rounded rather than acute. The male genitalia of F. sooretama sp. nov. and F. occultus are conspicuously different: in the former the penis is enlarged at apex and the apical lobes of tegmen are not emarginated (each lobe has only a small excavation in the outer edge). Individuals of F. sooretama sp. nov. were found inside the basidiomes of an unidentified species of Hymenochaetaceae, possibly belonging to Phellinus . We also provide additional geographic records and an updated identification key to all Falsocis species.