With the development of industry, agriculture, exploitation of natural sources and with boom of settlement density, the environment is being affected by potentially toxic elements; the phenomenon is consequently reflected on human health. Cadmium is a high risk element for the whole environment. The aim of this research was to analyse and evaluate sediments of selected water reservoirs during the ten-year period in order to determine the concentrations of selected, potentially toxic elements. For statistical processing, the correlation coefficient by the Spearman method and the analysis of the index were used. Sediments are reliable indicators of environmental pollution. The analyses of the sediment samples were carried out by the flow electrochemistry and the atomic absorption spectrometry methods. The total concentration of Cd in sediments was up to 22.60 mg kg⁻¹ of dry matter. pH/KCl was marked in the range from 5.6 to 7.2. From statistical processing of sediments data by Spearman, we determined the dependencies between Cd and the following elements: As, Cu, Hg, Pb and Zn. The relations between Cd and the following elements: Pb, As and Cu were very highly positive.