A SMX static mixer was used to disperse highly viscous Newtonian liquids into less viscous, Newtonian and non-Newtonian fluids without surfactants. The investigation covered the effect of the dispersed phase volume fraction, the viscosity ratio between the phases, the mixer length and the power draw. The flow regime was kept laminar in all the experiments with a dispersed phase content up to 25% and viscosity ratios ranging from 1 to 400. The experimental conditions allowed neglecting the affect of coalescence mainly because of the high viscosity of the continuous phase. The effect of the dispersed phase viscosity and volume fraction on the average drop size was quantified. The size distributions were obtained by image analysis. Using the 'process viscosity' concept, it was possible to collapse all the average diameters on a single master curve by using the energy consumption in the mixer as the shift variable between the experiments. A performance comparison against the Kenics mixer was made using literature results. The results showed that the SMX mixer is much better adapted to the dispersion task mainly due to its internal structure.