For uncertain time delay systems with mismatch disturbances, this paper presented an integral sliding mode control algorithm using output information only. The proposed control algorithm can improve the synthesis problem in past researches and avoid solving a large LMI. An integral sliding surface is comprised of output signals and an auxiliary full-order compensator. The designed output feedback sliding mode controller can satisfy the reaching and sliding condition and maintain the system on the sliding surface. Since the system is in the sliding mode and two specific algebraic Riccati inequalities are established, the proposed algorithm can guarantee the stability of the closed-loop system and satisfy the property of disturbance attenuation. Finally, a numerical example illustrated the applicability of the proposed scheme.