We tested the activities of anidulafungin and other antifungal agents against clinical isolates of different fungal species. For Candida species, high sessile MIC₉₀s (SMIC₉₀s) were obtained for fluconazole, voriconazole, and amphotericin B, whereas the anidulafungin SMIC₉₀s were very low, as were those for caspofungin. Comparatively, for Aspergillus species, higher SMIC₉₀ values were obtained not only for amphotericin B and voriconazole but also for the echinocandins.