Evaluation of the influence of leachate on underground waters in the vicinity of a chosen landfill is examined in this paper. The purpose of the research was to give information on maximum pollutants concentrations which could penetrate ground and water subsoil and its influence on the area adjacent to the landfill. Scale and range of pollution in the examined area have been observed in 7 piezometer test wells and 4 nearest household wells and analogous parameters have been determined for leachate. To evaluate the influence of leachate on examined ground waters a method of multidimensional factor analysis with Varimax rotation was used.