This paper presents a multirate output feedback based sliding mode control, algorithm which eliminates the chattering. The proposed algorithm uses the output samples for the switching function evaluation and sliding mode control computation. The control is based on the reaching law approach and drives the system trajectory to sliding manifold in finite time. The control law obtained has two parts, nonlinear and linear. The nonlinear part brings the trajectory in the vicinity of the sliding manifold and linear control guarantees that the sliding manifold is reached in one step and thereafter the motion of the system confines to the manifold. The proposed algorithm does not require knowledge of the complete state vector. As in many practical situations, all the states are not available for measurement: the proposed algorithm gives better choice for obtaining similar result. The algorithm is applied to a dc motor system with position measurement only.