Nonlinear inferential control (NLIC) has been developed as a method for improving control of nonlinear systems. The controller is modelbased, and allows for direct use of available measurements. This paper presents the structure of NLIC and the manner in which it is applied to processes when the controlled variables are measured. Also described is the improvement in the process control using NLIC. Two illustrative examples are presented, a laboratory heat exchanger process and a simulated neutralization process. The results indicate that a substantial improvement in control is possible using NLIC.