Azole resistance is an increasing clinical problem for Aspergillus fumigatus, with the majority of published resistance arising from mutations in the azole target gene CYP51A. Previous structural studies of this protein have suffered from a nonorthologous, low-homology template for homology modeling. Here we present a new model based on the human CYP51A orthologue that provides a higher-quality model for A. fumigatus CYP51A. Copyright © 2011, American Society for Microbiology. All Rights Reserved.