The viscous mixing characteristics of the Ekato Paravisc are compared with those of an anchor and a double helical ribbon. The methodology is based on 3D CFD finite element-based simulations. The predictions are first validated by comparing the Newtonian and non-Newtonian power consumptions and mixing times against literature experimental data. Then, the computed 3D laminar flow patterns and several mixing performance criteria (power consumption, pumping capability, intensity of segregation, mixing time, mixing efficiency and specific energy) of the impellers are investigated. It is shown that the Paravisc mixer characteristics lie between that of the other impellers at low Reynolds number. (c) 2005 Elsevier Ltd. All rights reserved.