An adaptive actuator failure compensation scheme is developed for control of a class of nonlinear multi-input multioutput systems with redundant actuators subject to uncertain failures. A new feature of this adaptive control scheme is the adaptation of the failure pattern parameter estimates, together with that of the failure signal parameter estimates, for direct adaptive actuator failure compensation, without explicit failure detection. It is shown that such an adaptive design is able to ensure the desired closed-loop stability and asymptotic output tracking despite the actuator failure uncertainties. Simulation results from its application to attitude control of a near space vehicle dynamic model are presented to verify the desired system performance with adaptive actuator failure compensation.