The oesophageal epithelium appears to be one of the primary cell targets of Candida albicans in AIDS patients. To study this interaction, we have established an in vitro adherence assay using a human epithelial oesophageal cell line (HET1-A). When yeast cells were grown in 500 mM D-galactose, adherence increased significantly over cultures prepared in 500 mM D-glucose. kDa was observed in Aurodye-stained SDS-PAGE gels and in Western blots using an immunoglobulin fraction (IgG) prepared from sera of rabbits infected with the organism. These studies demonstrate that C. albicans adheres to human oesophageal cells and may utilize cell surface proteins whose synthesis is nutritionally regulated.