Solubilities of alpha-lactose in water-ethanol solvent mixtures were obtained using an accurate analytical method, at 25, 40 and 60 degrees C in a concentration range from 0 to 100 sugar-free wt.% of water. The alpha-lactose solubility is a strong function of the water concentration in the solvent mixture. It increases monotonically with temperature and with water concentration. The experimental data were correlated using a UNIQUAC-based model and were predicted using two different UNIFAC-based models.