Dynamic matrix control (DMC) is now widely used in industrial control, and when properly applied results in significant savings due to improved efficiency and reduced off-spec product. The objective of this paper is to implement MIMO DMC on a simulated diaphragm-type chlorine/caustic electrolyser. A comparison between the MIMO DMC and traditional multi-loop SISO PID control strategy shows greatly improved controller performance and cell efficiency using DMC, which will result in reduced operating costs and increase cell diaphragm lifespan.