Lack of imprecise nonlinear model of real-time systems is inevitable due to several simplifications made, neglected frictions, dead-zones, and saturation. One of the most well-known nonlinear control design tools to deal with uncertainties is sliding-mode control approach. In this method the desired behavior is defined in terms of a sliding manifold. The sliding manifold is stable, and the controller is designed to push system states to this manifold and maintain them on it. The convergence of the sliding manifold to zero usually occurs in finite time which necessitates the use of a switching function; with which the robustness of the system is improved. This chapter deals with the design of classical sliding mode controllers, adaptive sliding mode control approach and terminal sliding mode controllers.