This study evaluates the inorganic water quality of the Jukskei River from 1979 until 2002 in order to assess the geological and anthropogenic factors that have influenced the inorganic water quality of the Jukskei River. The non-polluted Little Jukskei River has been used as a baseline reference. The Jukskei River is characterised in the early 1980s by low pH values (3 to 4), high sulphate concentrations (up to 500 mg/L) and high concentrations of sodium, chloride, fluoride, orthophosphate, and nitrate. Potential pollution sources include the Central Rand area and industry situated along the Modderfontein Spruit. The water quality has subsequently improved over time as is demonstrated, in particular, by steadily increasing pH values up to 8+ and decreasing sulphate concentrations down to <200 mg/L. Orthophosphate, nitrate, sodium, potassium and chloride concentrations in 2002 were significantly lower than in 1979 but still higher compared to the Little Jukskei River. This may be explained by communal effluent input as a result of increased urbanisation in the Jukskei Catchment area.