In a prospective study 15 consecutive children and 12 HIV-infected mothers were examined according to their colonization with Candida species in the oral cavity and on the hands. From 39 samples a total of 49 Candida isolates could be recovered (26 C. albicans, 4 C. glabrata, 9 Rhodotorula rubra, 4 C. dubliniensis, 3 C. tropicalis, 2 C. famata, 1 S. cerevisiae). Antifungal susceptibility testing revealed fluconazole MICs from 0.09 microgram/ml to 100 micrograms/ml. Genotyping was done with an AP-PCR technique using the primer "M13" and "(GACA)4". From the mycologic culture identical yeast isolates were found in 10 families. However, with PCR typing identical findings were seen only in 5 families. A C. albicans isolate resistant to fluconazole in vitro was found in a child and the mother of the same family. It could be summarized that yeast strains are transmitted between HIV infected mothers and their children. With PCR typing diversity among yeast isolates could be demonstrated even between members of the same family.