Recent advances in non-invasive electrical stimulation technology including transcranial direct current stimulation (tDCS) have provided novel and low risk options to rehabilitate the impaired ability of the central nervous system (CNS) to process sensorimotor information. Furthermore, tDCS appears to enhance CNS connectivity and there is preliminary evidence indicating that patients with Parkinson's Disease (PD) may experience improvement in working memory, the Unified Parkinson's Disease Rating Scale, simple reaction time and the Purdue Pegboard test. tDCS is inexpensive, portable and available for repeated home use. It may provide long-lasting enhancement of cortical activity in part because tDCS is easy to administer frequently and to combine it with other rehabilitation approaches including posture and gait training. However to date, no study has examined quantitatively the effects of tDCS on posture control and walking ability in patients with PD. As a first step we plan to identify the immediate effects of tDCS, as well as the added value of tDCS to treadmill exercise training, to improve posture and gait of individuals with PD.