This article presents the discrete adaptive quasi-sliding mode control of linear systems represented by the state space. The control scheme is a natural extension of the discrete adaptive sliding mode control scheme in that an additional design parameter is incorporated into the existing scheme to allow systematic modification of the amplitude of the control signal during the transient stage. A lemma, useful for establishing the stability of discrete adaptive quasi-sliding mode controllers, is given. The adaptive controller is shown to lead to a stable closed-loop system. Also, simulation results are presented to illustrate the features of the control scheme.