Numerical tools for the analysis of complex 3-D mixing devices were developed Calculations are based on the finite-element method. The flow calculation is combined with that of pathlines for a fairly large number of material points; along these pathlines, relevant kinematic variables, which are then subjected to a statistical treatment, are evaluated. These numerical techniques are applied to the analysis of a Kenics mixer. It is assumed that the geometry is periodic in the axial direction, that is, that the miter contains an infinite number of blades; the finite-element analysis may then be completed on a single wavelength of the geometry. To test the accuracy of the three-dimensional calculation, a Kenics device was mounted in order to mit clays of different colors, and photographs of experimental cross-sections were compared with numerical results showing concentration maps. A statistical treatment was performed on some 8, 000 material points crossing the entry section to evaluate miring quality.