In the dairy industry, crystallization is an important separation process used in the refining of lactose from whey solutions. In the refining operation, lactose crystals are separated from the whey solution through nucleation, growth, and/or aggregation. The rate of crystallization is determined by the combined effect of crystallizer design, processing parameters, and impurities on the kinetics of the process. This review summarizes studies on lactose crystallization, including the mechanism, theory of crystallization, and the impact of various factors affecting the crystallization kinetics. An overview of the industrial crystallization operation also highlights the problems faced by the lactose manufacturer. CLICK HERE for complete article. Journal of Food Science, Volume 79, Issue 3, pages R257–R272, March 2014.