The performance of the microstructured mixer Star-Laminator300 (StarLam300) with stacked star-shaped foils has been examined experimentally by the use of the adapted Villermaux/Dushman parallel-competitive iodide-iodate reaction system in continuous processes. The mixing efficiency was quantitatively determined by the segregation index derived from the UV absorption. The mixing performance of the microstructured mixer is analysed in terms of the total volume flow and turbulent energy dissipation rate. The influence of the geometry of the injection nozzles and the mixing chamber and the variation of foil number is also presented and discussed. The latter touches upon the numbering-up concept of microstructured devices. Since mixing efficiencies much better as for conventional equipment at throughputs up to 320 I h(-1) were found (with pressure-loss curves showing further potential to 1000 I h(-1)), this microstructured mixer proved potential to act as process-intensification (PI) equipment.