In order to determine the operating conditions leading to a product with a given particle size distribution, a study has been made of the influence of the operating parameters (stirrer speed, solids concentration, bends diameter) on the particle size distribution of the product obtained in wet fine grinding in a stirred bead mill. Combination of the results of this study with a flow model through the mill leads to a model of the continuous grinding process. This model suggests that the spreading of the particle size distribution could be reduced either in multiplying the number of mills associated in series, nor in multiplying the number of passages through the same mill. Experiments made with the same overall residence time confirm this assumption.