The solubility data of disodium 4,4'-dinitrostilbene-2,2'-disulfonate (DNSNa) in aqueous organic solutions (ethanol + water) and (ethylene diglycol + water) were investigated over the temperature range from (280 to 323) K using a dynamic method. The mole fraction of water in the two different solvent mixtures ranged from 0.2221 to 1.0000 and 0.5959 to 1.0000, respectively. The electrolyte nonrandom two-liquid (E-NRTL) model proposed by Chen was applied to model the solubility data Of DNSNa, in the above systems. The binary interaction parameters of the E-NRTL model were obtained via regression of the experimental solubility data. The root-mean-square deviations of determined equilibrium temperature and the calculated equilibrium temperature varied from (0.40 to 1.22) K.