Abstractand caries are frequently investigated among healthy and immunosuppressed individuals. The objective of this study was to demonstrate the presence of on both oral soft and hard tissue and to investigate, at molecular level, the genetic subtype of the organism from the two oral sites. Tongue swabs and dentine scrapings from 362 HIV-positive children, referred for extraction of carious primary teeth, were cultured on CHROMagar and identified to species level with ID32C. Histological staining of extracted carious teeth was also done. In patients with positive cultures from both the tongue and carious dentine, DNA fingerprinting of such paired isolates were performed, using Southern blot hybridisation with the Ca3 probe. Yeasts were cultured from the tongue of 151 (41.7%) individuals and 57 (37.7%) simultaneously yielded positive cultures from carious dentine. Nine different yeast spp. were identified from the tongue using the ID32C commercial system but was the only species recovered from carious dentine and histological investigation demonstrated fungal elements penetrated into the dentine and not limited to superficial debris on the floor of the cavity. Twelve of 13 paired isolates of revealed identical fingerprinting patterns. The findings from this study demonstrated that in a particular individual, the same genetic subtype of was capable of colonizing both oral soft tissue and carious dentine. This renders carious teeth a constant source, or reservoir, of potentially infectious agents and, particularly among immunosuppressed individuals, should therefore not be left unattended.