A two-parameter model, termed as a two-MSMPR-crystallizers-with-interchange model, is proposed in this paper to predict the overall performances of a nonideal, continuous-stirred crystallizer. The model equations, including the population balance equations and the mass balance equations, are solved simultaneously to predict the resulting crystal size distribution (CSD) for power law growth and nucleation kinetics. The effects of nonhomogeneous mixing, in terms of the two parameters, alpha and beta, on the weight-average size, the coefficient of variation and the production rate of the resulting crystals are studied. (c) 2006 Elsevier Ltd. All rights reserved.