The objective of the study was to determine the effect of cinnamon additive on the viability of two potentially probiotic bacterial strains: Lactobacillis rhamnosus K3 and Lactobacillus brevis 024 as well as on the sensory quality of probiotic pumpkin-apple mousses stored at 5 ºC for 21 days. The scope of the study included the production of probiotic pumpkin-apple mousses under the laboratory conditions, the determination of the count of probiotic bacteria of the two above named strains, measuring pH value and evaluating changes in the  sensory quality of products. Based on the analyses performed, it was found that the period time of storage had a significant effect on the  count of Lactobacillis rhamnosus K3 and Lactobacillus brevis 024 in the pumpkin-apple mousses regardless of the level of cinnamon  added. After 7 days of storing at 5 ºC, a statistically significant increase of 3 % was reported in the number of bacteria in all the products  analyzed except those containing the bacterial strain of Lactobacillis rhamnosus K3 and the cinnamon spice additive as was, at the same  time, a decrease in the pH value. The count of potentially probiotic bacterial strains of Lactobacillis rhamnosus K3 and Lactobacillus brevis O24 remained at a high level, i.e. above 7 log cfu /g of product during the entire time of refrigerated storage of pumpkin-apple mousse.  The cinnamon powder added in the amount of 6 % caused the overall sensory quality of the mousses to slightly decrease. It was proved  that those products had a higher intensity of other taste and flavour that was described as „cinnamon”. During the storage period, the  products were characterized by a high sensory quality (overall mean sensory quality was above 6.3 A.U.). The potentially probiotic strains of Lactobacillis rhamnosus K3 and Lactobacillus brevis O24 can be used to produce pumpkin-apple mousses with acceptable  sensory quality and a suitable number of bacterial cells to determine the probiotic properties of the end product.