The objective of the research study was to determine the effect of the oxidation level of potato starch on its acetylation and physicochemical properties. The starch was oxidised by chlorate(I) sodium at two concentrations: 10 and 20 g Cl per 1000 g d.m. of starch, and, next, acetylated using an acetic anhydride. The modified starches were examined as regards the effectiveness of the processes performed. In order to determine the physicochemical properties of the starches produced, the following was measured: water-binding capacity, solubility in water at a temperature of 50, 60, and 70 °C, and vulnerability of 2 % starch pastes to retrogradation. Moreover, the thermodynamic characteristics of gelatinization was determined using DCS. The rheological analysis comprised the characteristics of gelatinization using RVA and the intrinsic viscosity. Based on the results obtained, it was found that the level of potato starch oxidation had an effect on the acetylation effectiveness thereof. In all the starches, the acetylation process caused the parameter values of thermodynamic characteristics of the gelatinization, determined using DSC, and the vulnerability to retrogradation to decrease. What is more, the modifications applied had an effect on the changes in the physicochemical and rheological properties analyzed.