In this paper, the variable structure control (VSC) and switching-sigma adaptive laws are used to design a new robust controller for single-arm rigid manipulators in joint space. The controller is shown to be robust with respect to bounded disturbance. More particularly, a bound on the tracking error is determined and shown to be smaller than those resulting from the VSC law proposed in Slotine and Li as well as the robust adaptive control law derived in Reed and Ioannou. The simulations also show that the proposed control law has better tracking precision performance than the VSC law and switching-sigma, adaptive control law. It can also suppress chattering and maintain good tracking precision even if actuator unmodeled dynamics are considered.