Vaginal and vulva smears and urine obtained by catheters from 232 pregnant and 251 non-pregnant women were examined for the growth of yeasts. These fungi could be grown from the vulvo-vaginal smears from 26,7% of the pregnant women. Yeasts were found in 6,4% of the urine samples. In the case of non-pregnant women, fungi were found in 19,9% of the vulvo-vaginal smears, whereas 3,2% of the urine samples contained yeasts. The growth of yeasts was encouraged by the addition of various urine dilutions using to a nutrient solution containing Candida albicans of Torulopsis glabrata the urine obtained via catheters from both pregnant and non-pregnant women. There was no difference in the intensity of the effect between the two urine charges. Due to the relatively rare occurrence of yeasts in the urine from pregnant and non-pregnant women it suspected that the increased frequency of vaginal mycoses during pregnancy is not caused by a general disposition, but that locally effective factors are responsible.