Abstract Diabetes and pregnancy are thought to be independent factors increasing the risk of fungal infections. Objectives: The aim of the study was to evaluate the occurrence of fungal infection of the vagina, rectum and oral cavity in pregnant and non-pregnant women with and without diabetes. Material and methods: 627 women were included in the study, among them healthy non-pregnant women (HN), healthy pregnant women (HP), pregnant women with diabetes (PD) and non-pregnant women with diabetes (ND). In total, 1881 samples obtained from the vagina, rectum and oral cavity were tested. For species identification API 20 C i API C AUX tests were used. Results: Fungi in at least one locus were detected in 62,4% of all women, among them in 69,8% of HN, 58,5% of HP, 62,5% of PD and 62,7% of ND. Strains were isolated from vaginal samples of HP (16%) less often than in HN (27%) (95% CI 0,29-0,85; OR=0,5); in ND (31%) and PD (25%) there were no differences in the occurrence of fungi in the vagina (95% CI 0,37-1,38; OR= 0,71). Similar rates of prevalence of fungi in rectum were found in HN (30%) and HP (23%) (95% CI 0,43-1,16; OR=0,7) as well as in ND (27%) and PD (24%) (95% CI 0,41-1,64; OR=0,82). Strains have been isolated from oral cavity of 57% of HN and 54% of HP (95% CI 0,58-1,42; OR=0,9) as well as from 55% ND and 59% of PD (95% CI 0,65-2,21; OR=1,2). Conclusions: Lower prevalence of fungi in the vagina of HP, in comparison to HN, suggests a protective effect of pregnancy on the risk of vaginal mycosis. Pregnancy and diabetes independently have no influence on the prevalence of fungi in oral cavity and rectum.