This study presents a decoupled sliding mode controller for an inverted pendulum on a cart. The sliding mode control is a special type of variable structure control and it is applicable to the systems represented in the canonical form. For the systems which are not represented by the canonical form such as the inverted pendulum, the decoupled form of the sliding mode controller can be used. In this study, a controller is designed using decoupled sliding mode control for an inverted pendulum. The simulation and experimental results justify that the decoupled sliding mode control is an effective way to control inverted pendulum.