The 14 alpha-sterol demethylase in the azole-resistant Candida albicans, strain Darlington, is less sensitive to the triazole ICI 153066 than are two azole-sensitive strains, A and B. However, there is no direct correlation between the IC50 values for triazole inhibition of the demethylase and IC50 values for growth. It appears that the basis of azole resistance in strain Darlington may not be explained solely on the basis of a lack of sensitivity of its 14 alpha-sterol demethylase enzyme, but that other target sites for azole may be altered or absent.