This paper introduces an Integral Sliding Mode (ISM) based Composite Nonlinear Feedback (CNF) controller for linear descriptor systems. CNF controllers are well known for guaranteeing good transient performance, while tracking. But, the CNF controllers developed so far for the descriptor systems are not robust to disturbances. Sliding mode controllers, on the other hand, are well known for its matched disturbance rejection capabilities. Hence, to improve the robustness of the CNF controllers for descriptor systems an ISM based approach is been used here so that robustness in presence of matched disturbances is guaranteed but at the same time inherent good transient performance capability of CNF controlled system is retained. Simulation results are also shown at the end to ascertain the effectiveness of the proposed method. © 2018