This paper deals with event-triggering based design of discrete-time sliding mode (DTSM) control for linear systems. Multirate output feedback based DTSM is designed with event-triggering strategy such that the system trajectories remain bounded in the vicinity of sliding manifold. An event-triggering rule is developed for DTSM which is evaluated only at periodic time intervals. The control is updated whenever the triggering instant is generated at these discrete time instants. It is shown that with this technique the system trajectories remain bounded. Also, in this triggering scheme there is always guaranteed Zeno free execution of triggering sequences as it is inherently discrete. Simulation results are shown to demonstrate the theoretical treatments of this paper. © 2016 IEEE.