An efficient and novel solution technique is presented for solving multi-dimensional population balance models. In addition to overcoming stiffness in the original system, the algorithm also reduces the computational load by proposing a priori semi-analytical solutions for a major part of the aggregation quadratures (calculations performed once at the start of the simulation). The new technique gives very good solution times, thereby removing the bottleneck from the computational method in the development of detailed population balance-based models for such complex processes. As the emphasis is on the numerical solution technique, simpler forms of the aggregation kernel are employed in the study. However, these kernels reveal crucial information for the optimization and control of the granulation process. (c) 2005 Elsevier B.V. All rights reserved.