Microscopic examination of scales from lesions on the ear of a white-tailed deer (Odocoileus virginianus) revealed the presence of fungal structures, gross appearance of which was consistent with the morphology of a dematiaceous mold. Nutrient agar cultures inoculated with such scales yielded Alternaria alternata. No other fungus was seen or isolated. Hyphalike elements were also noted in thin sections of the connective tissue of the ear. These data indicate a subcutaneous infection initiated by Alternaria.