The increased prevalence of oral candidosis associated with HIV infection must be intrinsically related to immunological changes in the host, but might also involve alterations to the infecting strains of yeast. This study aimed to determine if strains of Candida albicans isolated from asymptomatic HIV-infected individuals or AIDS patients possessed altered adherence properties in an in-vitro buccal epithelial cell (BEC) adherence assay. C. albicans isolates from 49 patients with HIV infection or AIDS adhered to BEC in significantly higher numbers than isolates from 49 control subjects (p < 0.001). No significant differences in adherence were detected between strains isolated from HIV-infected or AIDS subjects, or between strains isolated from C. Albicans carriers (low salivary C. albicans counts) or subjects with oral candidosis. The presence of whole saliva significantly inhibited the binding of candida to BEC (p < 0.001), but the significant difference in adherence between the HIV/AIDS and control isolates was maintained. The effect of saliva was independent of salivary candida antibodies and was abolished by treatment with protease or neuraminidase, suggesting the involvement of salivary mucins. The results of this study suggest that HIV infection is associated with the selection of strains of C. albicans with and increased ability to adhere to oral mucosa.