Treatment of an aqueous radioactive waste solution to remove radium prior to discharge was conducted at a laboratory scale. The actual solution is mainly composed of combined radium (226Ra and228Ra) with high concentrations of manganese, iron and calcium, which are present as chlorides in dilute hydrochloric acid. Direct precipitation by sulfate anions was selected to be the more viable treatment technique. Sulfate anion concentration, free acidity, temperature and aging of the sulfate precipitate in the supernate prior to filtration are factors that were investigated for their effect on the separation efficiency. The data obtained are discussed in detail.