The purpose of the paper was to identify and evaluate the impact of anthropogenic factors on water quality in a catchment with limited water quality data. The Serafa stream flowing through the Lesser Poland region was selected for the study. Changes in the content of 21 selected physico-chemical indicators were evaluated at five monitoring sites of the Serafa over a 12-month period.Cluster analysis, Kruskal-Wallis test, factor analysis with varimax rotation method, and surface water quality classification were used to develop the results.It was found that of the 21 physico-chemical indicators tested, for seven of them (EC, TDS, Cl-, Mg2+, Na+, K+ and pH), there were statistically significant differences between the values at point 1 and the ones at the other points (2-5), at monitoring site 1, the values of these indicators were lower compared to the rest of the catchment. The study of physico-chemical indicators showed that the water qualified for below good status, due to exceeded values of EC, BOD5, TDS, Cl-, Ca2+, Mg2+, pH, P–PO43-, N–NO2-. The evaluation of anthropogenic factors affecting the water resources of the catchment showed that the quality of water in the Serafa catchment is mainly influenced by improper wastewater management.