Five small catchments in the northern Prealps of Switzerland were investigated for variations of stream water chemistry during the years 1967 and 1968 using the stepwise multiple-regression technique. Concentrations of magnesium, potassium, silica, sulphate, chloride, nitrate, anunonium and pH value show little variation. Measurements of electrical conductivity, total hardness, and calcium, carbonate, and sodium concentrations indicate considerable variation. Discharge rate is found to account in three of the five streams for 80% or more of the variation or the five chemical components. However, the compound effect of discharge, water temperature and a factor estimating seasonal change of soil moisture conditions accounts in all five catchments for 71% to 95% of the variation. Differences between streams seem to be due to differences in vegetation cover and soil conditions of the respective catchments.