We analyzed the frequency of isolation of individual fungal species in the samples of urine, vaginal and cervical swabs from 107 patients (72% women and 28% men) aged 16-82 years, who were treated in primary care for cystitis, vulvovaginitis, and cervicitis. The samples were analyzed at the Microbiological Laboratory of Zagreb Institute of Public Health, Croatia, between September 1, 2002 and June 31, 2003. Eight species of yeast were isolated from the samples. Candida (C.) albicans, C. glabrata, and C. krusei were the most common isolates, with the frequency of 61.7%, 10.3% and 8.4%, respectively. Other species (C. guilliermondii, C. famata, C. tropicalis, C. parapsilosis, and C. kefyr) were less frequently isolated, between 0.9% and 7.5%. In women, the frequency of isolation of C. albicans species from urine samples ranged from 83.3% to 30.8%, and from uterine cervical swabs from 85.7% to 50%, showing a decreasing trend with patients' age. The frequency of C. albicans isolates from vaginal swabs was equal in younger (<30 years) and older women (ł51 years), but twice less frequent in middle-aged women. In men, the frequency of C. albicans species isolated from urine samples decreased with age from 100% to 52.4%. In the 107 analyzed samples with positive fungal culture, yeast isolations were significantly more frequent than pure culture (93.5%) and had a larger number of colony counts (57%). This suggested that these yeast species might have a pathogenic role in the causation of urogenital system infections.