Wangiella dermatitidis was isolated for the first time from the macroscopically asymptomatic internal organs of 2 Phyllostomus discolor, 1 Molossus molossus, 1 Sturnira lilium and 1 Myotis albescens among bats captured in the region of Manaus, Brazil. The dermatiaceous fungi isolated exhibited polymorphism at 25 and 37 degrees C, showing toruloid hyphae, integrated and terminal phialides without collarettes and yeast-like cells. The fungi did not hydrolyze gelatin, casein or starch. Some ecological aspects of bats in relationship to the epidemiology of phaeohyphomycosis are discussed.