Solid–liquid equilibria in mixed electrolyte aqueous solution have been investigated using available thermodynamic data for solids and for aqueous electrolyte solutions. The mean spherical approximation (MSA) modified by Lu et al. [Fluid Phase Equilib. 85 (1993) 81] is used to calculate the mean ionic activity coefficients in mixed electrolyte solutions at saturation conditions. Solid-liquid equilibria of seven mixed electrolyte systems at 298.15K are successfully predicted using the modified MSA method with the parameters obtained from activity coefficient data of corresponding single electrolyte solutions. The total average absolute deviation between predicted and experimental values is 5.58%. Furthermore, the predicted results of solid-liquid equilibria for four mixed electrolyte solutions over a range of temperature indicate that the modified MSA method can fairly be used to predict solid-liquid equilibria for mixed electrolyte aqueous solutions at various temperatures.