The objective of this study was to develop a pumpkin pulp fermented by probiotic bacteria as a semifinished product to be used to make sorbets. It was found that the optimal parameters for pumpkin pulp to ferment using one probiotic bacterial strain of Lactobacillus casei KN 291 are as follows: temperature: 32 °C; fermentation time: 26 h; sucrose additive: 8 %. The above fermentation parameters were applied and enabled to produce a pumpkin pulp of the highest overall sensory acceptance. During the fermentation process, the increase in the bacteria count occurred depending on the type of pumpkin pulp; this count increased to the value of 9.55 – 9.90 cfu /g. A higher Lactobacillus casei KN 291 count was reported in the pumpkin pulps with inuline, and this fact may evidence the preobiotic additive to have an advantageous effect of on the growth of bacteria.