A total of 61 isolates of dematiaceous fungi, including Exophiala jeanselmei, Wangiella dermatitidis, Fonsecaea pedrosoi, Phialophora verrucosa, and a few isolates of related organisms were evaluated for their ability to assimilate 13 carbohydrates and sodium nitrate. Results indicated that patterns of assimilations can facilitate specific identifications when used with microscopic morphologic features. Eleven isolates of W. dermatitidis demonstrated negative results for nitrate assimilation, although most of the other fungi tested had positive reactions. The tests did aid in separating this very complex group of fungi.