Whey is the one of the byproducts of cheese-making. Due to the high nutrient content of whey, it is being used to prepare many different products. Probiotic bacteria have been used to develop new whey containing beverages so new generation-products can be produced which influence the human health positively. The aim of this study was to define the growth and survival of probiotic microorganisms, Lactobacillus plantarum AA1-2 and Saccharomyces boulardii, in whey. The whey was inoculated and fermented with L. plantarum AA1-2, S.boulardii bacteria separately and mixture of these two bacteria was also used. Microbial counts, changes in pH values and sensory quality were analysed in the beverages. Beverages with the highest sensory scores were analysed to determine aroma compounds by using GC/MS-SPME. While pH value of reconstituted whey was 6.15, pH values of fermented beverages were diminished and ranged from 4.97 to 6.07. Yeast count was higher than 10(5) cfu/ml, and bacteria count were between 10(7)-10(8) cfu/ml. The best result of the sensory properties of beverages was occured at 2% inoculation of L. plantarum AA1-2. According to the results obtained with GC/MS-SPME, the highest amount of aroma compounds found in whey was acetate isopropyl.