Zone diameters for anidulafungin by disk diffusion for 139 isolates of C. parapsilosis were compared with MICs by NCCLS M27-A2 broth microdilution. The comparison was poor unless the disks were prepared by dissolving anidulafungin in 1% dimethyl sulfoxide plus 0.1% Tween 80 and testing on Mueller-Hinton agar flooded with glucose and methylene blue.