The objective of the study was to characterise the quality of surface waters in order to de-termine their vulnerability to pollution by nitrogen compounds from agricultural activity, as well as to specify the areas with increased exposure, where nitrogen runoff from agricultural sources has to be reduced. It was necessary to determine surface waters liable to pollution by these compounds due to the fact that agricultural production should be carried out in the way which limits and prevents water pollution by nitrogen compounds of agricultural origin. The study addressed the following is-sues: the concentration of nitrogen compounds in the surface waters of the Middle Odra Basin, and the extent of eutrophication in flowing inland waters (with nitrogen as the main nutrient). The results have been plotted in figures and gathered in tables.