The in vitro susceptibilities of 59 avian Aspergillus fumigatus strains to amphotericin B, itraconazole, and voriconazole were determined using the standard microdilution broth method (CLSI M38-A2). Four isolates showed acquired resistance to itraconazole and voriconazole, harboring implications for the treatment of aspergillosis in both birds and humans.