The objective of this paper was an attempt to explain a phenomenon occurring during the osmotic dehydration of pumpkin in a solution of glucose and starch syrup. The effect was determined of the kind of osmotic substance (glucose, starch syrup) and the concentration (20 and 60 %) of its solution on the kinetics of osmotic dehydration of pumpkin. The dehydration process was carried out at a raw substance/osmotic solution ratio of 1:4 during a period from 0 to 300 min. In order to describe the process, the following parameters were calculated: water content, water loss, solid gain, and water loss/solid gain ratio. The results obtained show that both the kind of osmotic substance and the changes in its concentration from 20 to 60 % in the solutions impact the kinetics of osmotic dehydration of pumpkin. With the 60 % solutions applied, the effectiveness of the process was higher for the starch syrup solution, and with the 20 % solutions – for the glucose solution.