This work implements a real-time MIMO (Multiple Input Multiple Output) nonlinear predictive controller applied to a water tank plant to control the water level and temperature in the tank using as control forces the rate of inflow of the water and the heat supplied by an electrical resistance. For comparison purposes, this work also implements a MIMO PID (Proportional Integral Derivative) controller. Experimental results demonstrate that the MIMO nonlinear predictive controller performs better than the MIMO PID controller because employing the former controller, the settling time, the percent overshoot, as well as the steady-state error of the controlled outputs decrease.