In 1991, a novel robot named MIT-MANUS was introduced as a test bed to study the potential of using robots to assist in and quantify the neuro-rehabilitation of motor function. It proved an excellent fit for the rehabilitation of shoulder and elbow of stroke patients with results in clinical trials showing a reduction of impairment in these joints. The greater reduction in impairment was limited to the group of muscles exercised. This suggests a need for additional robots to rehabilitate other degrees of freedom. This paper outlines the mechanical design of a robot for wrist rehabilitation.