The in vitro activities of eight antifungal drugs against clinical isolates of Fonsecaea pedrosoi (n ؍ 21), Fonsecaea monophora (n ؍ 25), and Fonsecaea nubica (n ؍ 9) were tested. The resulting MIC 90 s for all strains (n ؍ 55) were as follows, in increasing order: posaconazole, 0.063 g/ml; itraconazole, 0.125 g/ml; isavuconazole, 0.25 g/ml; voriconazole, 0.5 g/ml; amphotericin B, 2 g/ml; caspofungin, 2 g/ml; anidulafungin, 2 g/ml; and fluconazole, 32 g/ml.