OBJECTIVE The presence of yeasts in periodontal pockets has been described in a few studies. The association between yeasts and putative periodontal pathogens is not well described. This study aims at assessing the prevalence of yeasts in periodontal pockets and possible associations with the clinical conditions of the sampled sites and other micro-organisms present. METHODS 2 subject groups form the basis for this study. The 1st comprises results from microbiological samples from periodontal pockets of 128 subjects. The 2nd originates from 126 periodontal patients with untreated pockets. Microbiological identification was performed after cultivation on blood and Sabouraud agar plates, and "checkerboard" DNA-DNA hybridisation. RESULTS The prevalence of subjects with yeasts in the pockets was 15.6% and 17.5% in the 2 groups respectively and was inconsistent according to gender. No correlation was found between age and the presence of yeasts. Eubacterium saburreum was weakly correlated with presence of yeasts (r=0.194 p=0.03). Yeasts were rarely found in both samples from the same individual. CONCLUSIONS Our results indicate that yeasts can be expected to be present in periodontal pockets in one out of 6 periodontal patients independent of gender and age. Eubacterium saburreum seems to occur frequently together with yeasts.