The object of this study were to determine the effect of apple and lemon fibers on the physical, chemical, microbiological and sensory properties of low fat kefir and to investigate whether or not the probiotic properties of the samples were maintained throughout storage period of 20 days at 4 degrees C. Low fat UHT cow's milk was mixed with apple fiber (1-2 %) and lemon fiber (1-2 %). Control sample wasn't mixed with any fiber. Milks were inoculated with 4-percent kefir culture and fermented up to pH 4.7 at 25 degrees C. Differences were obtained in the levels of dry matter, fat, lactose, ash, pH, SH and tyrosine of kefir samples supplemented with or without apple or lemon fibers at different concentrations (P > 0.05). While the addition of apple and lemon fiber at lower concentrations increased the viscosity in kefir, viscosity was decreased at higher levels (P < 0.05). Supplementation of kefir with fibers did not adversely affect the counts of Lactobacillus spp. and Lactococcus spp. (P < 0.05). More research is needed to improve the organoleptic properties of the kefir samples supplemented with apple and lemon fibers.