Virtual reality systems have been used to deliver goal directed repetitive training to promote rehabilitation of individuals post-stroke. Lower extremity training of individuals post-stroke who used a robot coupled with virtual environment has been shown to transfer to improved overground locomotion. To isolate the active components of training in this study we compared the outcomes of training with the robot-virtual reality (VR) system to the robot alone. Four individuals post-stroke participated in a four-week training protocol. One group trained with the robot-VR system and the other group with the robot alone. The improvement in walking speed and endurance for the robot- VR group was greater than the robot group alone. Adherence as well as the number of exercises performed in each session was comparable for the two groups. The duration of training sessions was comparable at the beginning of the study. However, subjects in the robot group reported higher fatigue and produced 16% fewer minutes of training towards the end of the study. These findings support the use of virtual environments coupled with a robot for transfer of training from the virtual to the real world environment.