We compared a unilateral robot-assisted training protocol (URTP) and a bilateral robot-assisted training protocol (BRTP) to study their differential effects. We recruited 21 patients with stroke who received 90–105 min of therapy 5 days/wk for 4 wk. Participants in the URTP and BRTP groups practiced forearm pronation and supination and wrist flexion and extension in a simultaneous manner with the Bi-Manu-Track. The control group received standard rehabilitation. Clinical measures included the Fugl-Meyer Assessment, the Medical Research Council instrument, grip strength, and the Modified Ashworth Scale to assess motor impairment, muscle power, muscle strength, and spasticity, respectively. The pilot study indicated that the URTP and BRTP might have differential benefits for movement improvement. URTP might be a more compelling approach to improving upper-limb motor impairment, muscle power, and strength at the distal joints than BRTP, whereas BRTP could be an optimal approach to improving proximal muscle power.