The design and implementation of a robust control algorithm for slow non-linear processes are presented. The algorithm is derived using the pole placement approach and the dominant roots concept. In particular, the presence of an integral action—in the three-term controller—on the error ensures robust offset rejection for any constant load disturbance acting on the plant. The algorithm is shown to be practical, robust, and successful for slow time-delay process regulation. A simulation example illustrates the main features of the method.