The Candida albicans HOG1 gene (HOG1(Ca)) was cloned by functional complementation of the osmosensitive phenotype associated with Saccharomyces cerevisiae hog1 Delta mutants. HOG1(Ca) codes for a 377-amino-acid protein, 78% identical to S. cerevisiae Hog1p. A C. albicans hog1 null mutant was found to be sensitive to osmotic stress and failed to accumulate glycerol on high-osmolarity media.