Computational fluid dynamics is applied to calculate flow velocities, pressure drops, residence time distributions and heat transfer in a three-dimensional model of the Sulzer SMX static mixer for both Newtonian and non-Newtonian power-law fluids. A duct with a square cross-section is used with 2, 4 and 8 sections of three plates each per mixing element. The velocity profiles are shown in various cross-sections. The calculated pressure drop agrees with experimental results. Calculated heat transfer coefficients for cooling through the wall appeared to be lower than the experimental values due to the fact that heat conduction in the plates was neglected. Simulation with infinite conductivity of the plates resulted in higher heat transfer coefficients than experimentally observed. Simulation of the residence time distribution by means of particle tracking gave mass Peclet numbers of 4.2 per SMX element, which agrees well with experimental values.