This article presents the results of concentrations of N-NO₂, N-NO₃, Cl^¯, SO₄^2-, P-PO₄, N-NH₄, Fe, chemical oxygen demand with KMnO₄, HCO₃^¯, P_total, acid neutralizing capacity between the pH range of 4.5 and 3.5 along with pH and electrolytic conductivity for Štiavnica Stream (in south-central Slovakia). These parameters were monitored at four monitoring places (Banská Štiavnica, Svätý Anton, Prenčov, and Hontianske Nemce) from 2006 to 2008. The rank order of soluble nitrogen forms on the basis of median values were in Banská Štiavnica N-NH₄>N-NO₂>N-NO₃, in Svätý Anton, Prenčov and Hontianske Nemce N-NO₃>N-NH₄>N-NO₂. The concentration of phosphates phosphor was high in all sampling places, with the highest in Banská Štiavnica (0.29 mg·L^-1). Physico-chemical parameters such as pH were in the interval from 6.52 to 7.93, electrolytic conductivity and chemical oxygen demand were highest in Banská Štiavnica (EC = 51.51 mS·m^-1, CODMn = 10.46 mg·L^-1). The aim of our article is to prove, according to our analyses, that surface water quality has gotten worse and to point out the importance of monitoring smaller streams that are permanently contamined by local settlements.