Wiener models consist of a linear dynamic element followed by a static non linear element. This paper shows a non linear model predictive control (NMPC) based on a piecewise linear; the Wiener model is applied on an experimental control of pH. The static nonlinear element of the Wiener model is approximated using piecewise linear function. Identification using optimal local linear model is applied and parameter estimation as well as partitioning of the local linear models is simultaneously obtained. The techniques are then applied to an experimental control of pH and the performance of NMPC is shown. © 2011 IFAC.