The solubility diagrams of four-component water-salt systems of the type H+, Me1n+, Me2m+ || Cl--H2O (Mein(m)+ = Na+, K+, Mg2+, Ca2+, Sr2+, Ba 2+) were calculated at 25°C using the Pitzer equations. The calculation results were in convincing agreement with the few experimental solubility data available from the literature.