A study was conducted of the growth of Saccharomyces (S.) and non-Saccharomyces populations during alcoholic fermentation of Emir and Kalecik karasi grape varieties in the 1998 and 1999 vintages. Kloeckera (Kl.) apiculata, Kluyveromyces (K.) thermotolerans, S. cerevisiae and Candida (C.) pulcherrima were the dominant yeasts in fermentation of the 1998 vintage in Emir must. Kl. apiculata and K. thermotolerans proliferated at the beginning of the fermentation. The number of these yeasts eventually decreased when S. cerevisiae appeared as the dominant yeast on day four. But they remained until the end of the fermentation. Kl. apiculata, C. dattilla, C. pulcherrima, C. krusei and S. cerevisiae were found during the fermentation of the 1999 vintage Emir must. The count of S. cerevisiae was very high in the juice, but after skin fermentation and cold treatment, it disappeared and could not be isolated until day six of the fermentation. Kl. apiculata and C. dattilla were the dominant yeasts until S. cerevisiae started proliferation after the middle of the fermentation. Kl. apiculata, Metschnikowia (M.) pulcherrima, S. cerevisiae, C. holmii, C. valida, C. guillermondii and Candida sp. were isolated during the fermentation of Kalecik karasi must in 1998. Kl. apiculata, C. pulcherrima, S. cerevisiae, C. holmii and C. valida were identified in fermentation of must in the 1999 vintage.